POLISHING MATERIAL SUPPLY SYSTEM AND RELATED METHODS

Description

BACKGROUND

Semiconductor devices are formed on, in, and/or from semiconductor wafers, and are used in a multitude of electronic devices, such as mobile phones, laptops, desktops, tablets, watches, gaming systems, and various other industrial, commercial, and consumer electronics. One or more semiconductor fabrication processes are performed to form semiconductor devices on, in, and/or from a semiconductor wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 illustrates a perspective view of a system comprising a polishing apparatus, in accordance with some embodiments.

FIG. 2 illustrates a schematic view of a polishing liquid supply system, in accordance with some embodiments.

FIG. 3 illustrates a schematic view of a supply tank having a liquid level sensor assembly thereon relative to other components of a polishing liquid supply system, in accordance with some embodiments.

FIG. 4A illustrates a method of adjusting refill level and mix-in volume of a polishing liquid supply system, in accordance with some embodiments.

FIG. 4B illustrates a method of adjusting refill level and mix-in volume of a polishing liquid supply system, in accordance with some embodiments.

FIG. 5 illustrates a schematic view of a slurry delivery monitoring system, in accordance with some embodiments.

FIG. 6A illustrates a schematic view of a scenario in which a computer determines polishing liquid supply parameters associated with a polishing liquid supply system, in accordance with some embodiments.

FIG. 6B illustrates a schematic view of a system operable to determine polishing liquid supply parameters and manufacturing schedule associated with a polishing liquid supply system, in accordance with some embodiments.

FIG. 7A illustrates a schematic view of a training module training a machine learning model to generate a trained machine learning model, in accordance with some embodiments.

FIG. 7B illustrates a schematic view of a trained machine learning model evaluating data to determine polishing liquid supply parameters associated with a polishing liquid supply system, in accordance with some embodiments.

FIG. 8 is a flow diagram illustrating a method of operating a polishing liquid supply system, in accordance with some embodiments.

FIG. 9 is a flow diagram illustrating a method, in accordance with some embodiments.

FIG. 10 is a flow diagram illustrating a method, in accordance with some embodiments.

FIG. 11 illustrates an example computer-readable medium wherein processor-executable instructions configured to embody one or more of the provisions set forth herein may be comprised, according to some embodiments.

DETAILED DESCRIPTION

The following disclosure provides several different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to other element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation illustrated in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

The term “overlying” and/or the like may be used to describe one element or feature being vertically coincident with and at a higher elevation than another element or feature. For example, a first element overlies a second element if the first element is at a higher elevation than the second element and at least a portion of the first element is vertically coincident with at least a portion of the second element.

The term “underlying” and/or the like may be used to describe one element or feature being vertically coincident with and at a lower elevation than another element or feature. For example, a first element underlies a second element if the first element is at a lower elevation than the second element and at least a portion of the first element is vertically coincident with at least a portion of the second element.

The term “over” may be used to describe one element or feature being at a higher elevation than another element or feature. For example, a first element is over a second element if the first element is at a higher elevation than the second element.

The term “under” may be used to describe one element or feature being at a lower elevation than another element or feature. For example, a first element is under a second element if the first element is at a lower elevation than the second element.

With progress in advanced semiconductor process nodes, slurry freshness control is increasingly beneficial for chemical mechanical polishing (CMP). For example, slurry freshness can affect removal rate, which is a measure of how quickly material is removed from a surface of a wafer that can be quantified in units such as nanometers per hour (nm/h) or angstroms per minute (Å/min). Polishing slurry is typically stored in supply tanks and optionally in buffer tanks on the way to being supplied to CMP apparatuses for use in polishing wafers. The polishing slurry has a lifetime or shelf expiration associated therewith. For example, after dilution and mixing with one or more additives, new polishing slurry is combined with old polishing slurry and an aging period is selected over which chemical reactions in the aging polishing slurry can reach a beneficial state of completion. Improperly aged polishing slurry can affect removal rate, which can lead to slowing of wafer manufacturing production.

Storing the aging polishing slurry in the buffer tank(s) and/or supply tank(s) can lead to challenges. Polishing slurry that has aged past a usable quality timeframe is dumped while fresh polishing slurry is mixed in, which causes waste and cost increases. Polishing slurry being below the usable quality can cause production halts while waiting for the polishing slurry to age to a beneficial quality level.

In embodiments of the disclosure, the supply tanks, the buffer tanks, or both include continuous liquid level gauges and a weight scale, which can each supply data for adjusting aged polishing slurry in real-time. The adjusting can include adjusting a refill level, a mix-in amount (e.g., weight or volume) or both. The refill level can be a level at which fresh polishing slurry is mixed in to aged polishing slurry in the buffer tank(s) and/or supply tank(s). The mix-in amount can be an amount of fresh polishing slurry that is mixed in to the aged polishing slurry in the buffer tank(s) and/or supply tank(s). In some embodiments, wafer production levels are fed into a slurry supply control module to provide precise selection of the mix-in amount.

FIG. 1 illustrates a system 100 comprising a polishing apparatus 160, according to some embodiments. FIG. 2 illustrates a liquid supply system or “polishing liquid supply system” 200 that can supply slurry to the system 100, according to some embodiments. In some embodiments, the polishing apparatus 160 is configured to perform a first polishing process to polish a first semiconductor wafer 132. In some embodiments, the first polishing process comprises a chemical mechanical planarization (CMP) process. In some embodiments, the polishing apparatus 160 comprises a CMP tool. In some embodiments, the first polishing process is performed to homogenize and/or planarize a first surface of the first semiconductor wafer 132 using a combination of chemical and mechanical forces. Embodiments are contemplated in which items different than a semiconductor wafer are polished using the polishing apparatus 160. The polishing system 100 and liquid supply system 200 are described in detail herein to provide context for understanding embodiments of a polishing material supply system and related methods that are described with reference to FIGS. 2-11.

In some embodiments, the polishing apparatus 160 comprises at least one of a platen 110 configured to support a polishing pad 120, the polishing pad 120 configured to be rotated by the platen 110, a polish head 130 configured to support the first semiconductor wafer 132 in a polishing position relative to a polishing surface 121 of the polishing pad 120 for polishing of the first semiconductor wafer 132, a pad conditioner 102 configured to condition the polishing pad 120, or a slurry provider 122 configured to provide a slurry 134 to the polishing surface 121 of the polishing pad 120. The slurry 134 may also be referred to as a “polishing material,” and while typically a slurry, may also be another suitable liquid polishing material or composition. FIG. 1 depicts the first semiconductor wafer 132 in the polishing position in accordance with some embodiments.

In some embodiments, the first semiconductor wafer 132 comprises at least one of a substrate, a photomask, a semiconductor device, a dielectric layer, an epitaxial layer, a silicon-on-insulator (SOI) structure, a semiconductor layer, a conductive material layer, a die, etc. The first semiconductor wafer 132 comprises at least one of silicon, germanium, carbide, arsenide, gallium, arsenic, phosphide, indium, antimonide, SiGe, SiC, GaAs, GaN, GaP, InGaP, InP, InAs, InSb, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, GaInAsP, or other suitable material. The first semiconductor wafer 132 comprises at least one of monocrystalline silicon, crystalline silicon with a <100> crystallographic orientation, crystalline silicon with a <110> crystallographic orientation, crystalline silicon with a <111> crystallographic orientation or other suitable material. Other structures and/or configurations of the first semiconductor wafer 132 are within the scope of the present disclosure. In some embodiments, the first polishing process performed using the polishing apparatus 160 polishes the first surface of the first semiconductor wafer 132 comprising at least one of a surface of the substrate, a surface of the photomask, a surface of the semiconductor device, a surface of the dielectric layer, a surface of the epitaxial layer, a surface of the SOI structure, a surface of the semiconductor layer, a surface of the conductive material layer, etc.

In some embodiments, the polishing pad 120 is configured to be driven by the platen 110 to rotate in a first rotational direction 154 about an axis 150. In some embodiments, the polishing pad 120 and the platen 110 rotate synchronously in the first rotational direction 154 about the axis 150. In some embodiments, the platen 110 is rotated using a first driving mechanism (not shown), such as a motor configured to drive a cylinder 140 coupled to the platen 110, to rotate the polishing pad 120 about the axis 150.

In some embodiments, the slurry provider 122 comprises at least one of a slurry provider arm 125 or a slurry outlet 123. In some embodiments, the slurry outlet 123 comprises a nozzle. In some embodiments, the slurry provider arm 125 controls a position of the slurry outlet 123 relative to the polishing surface 121 while providing the slurry 134 to the polishing surface 121 of the polishing pad 120. In some embodiments, the slurry provider 122 is connected to a slurry supply system or “liquid supply system” 200 described with reference to FIGS. 2-7B. The slurry supply system 200 contains the slurry 134, which is conducted from the slurry supply system 200 to the slurry outlet 123 for application to the polishing pad 120. In some embodiments, the slurry 134 comprises a liquid comprising at least one of one or more polishing particles or one or more reactive chemicals.

The slurry 134 may include one or more of a slurry base liquid, a diluting liquid and additive liquids that are mixed in a mixing container prior to delivery to the slurry outlet 123. The mixed slurry may be transported to a supply tank(s) and optionally to a buffer tank(s) positioned prior to the supply tank(s). While stored in the supply tank(s) and optionally the buffer tank(s), the mixed slurry or “polishing slurry” may be aged. Aging is a process by which additives in the polishing slurry react chemically with one or more materials of the polishing slurry to achieve one or more selected parameters. Within a selected window of time, aged polishing slurry may be supplied to the slurry outlet 123 for beneficial polishing of the first semiconductor wafer 132. When production volume is low, some of the aged polishing slurry may extend past the selected window of time and is dumped, leading to waste and increased cost. Embodiments of the disclosure provide for precise control of a refill level and mix-in amount based on data associated with the polishing slurry, production volume, CMP tools, and the like. It should be understood that “refill” includes the meaning of “add slurry” without requiring that a tank that is being refilled is filled entirely. Namely, “refill” includes partial refill and full refill.

The polishing pad 120 comprises a porous material, such as porous polyurethane foam. Other materials of the polishing pad 120 are within the scope of the present disclosure. In some embodiments, a hardness of the polishing pad 120 is at least one of (i) harder than a first threshold hardness to allow at least one of the polishing pad 120 or the slurry 134 to polish, such as mechanically and/or chemically polish, the first surface of the first semiconductor wafer 132, or (ii) softer than a second threshold hardness to mitigate scratching the first surface of the first semiconductor wafer 132. In some embodiments, the polishing pad 120 is removably coupled to the platen 110. In some embodiments, the polishing pad 120 is coupled to the platen 110 using an adhesive.

In some embodiments, the polish head 130 comprises at least one of a wafer holder 128, a polish head cylinder 124, or a wafer holder union 126 between the wafer holder 128 and the polish head cylinder 124. In some embodiments, the polish head 130 exerts a wafer polishing force onto the first semiconductor wafer 132 in a direction 152 towards the polishing pad 120. In some embodiments, the direction 152 of the wafer polishing force is about parallel to the axis 150. In some embodiments, when the first semiconductor wafer 132 is in the polishing position relative to the polishing surface 121, the first semiconductor wafer 132 is in contact with the polishing surface 121. In some embodiments, the polish head 130 is configured to rotate at least one of the wafer holder 128 or the first semiconductor wafer 132 in a second rotational direction 156. In some embodiments, the first rotational direction 154 and the second rotational direction 156 are the same rotational direction (e.g., clockwise or counterclockwise). Embodiments are contemplated in which the first rotational direction 154 and the second rotational direction 156 are different rotational directions (e.g., one is clockwise and the other is counterclockwise). In some embodiments, the first semiconductor wafer 132 is rotated by the polish head 130 using a second driving mechanism (not shown), such as a motor configured to drive the polish head cylinder 124.

In some embodiments, during the first polishing process, at least one of (i) the slurry provider 122 provides the slurry 134 to the polishing surface 121, (ii) the first semiconductor wafer 132 and the polishing pad 120 are rotated, or (iii) the slurry 134 flows between the first semiconductor wafer 132 and the polishing pad 120 as the first semiconductor wafer 132 and the polishing pad 120 are rotated. In some embodiments, the first polishing process polishes the first surface of the first semiconductor wafer 132 by at least one of (i) mechanical force between polishing particles of the slurry 134 and the first surface of the first semiconductor wafer 132, (ii) mechanical force between the polishing pad 120 and the first surface of the first semiconductor wafer 132, or (iii) chemical reaction between reactive chemicals of the slurry 134 and the first surface of the first semiconductor wafer 132.

In some embodiments, the pad conditioner 102 comprises at least one of a pad conditioner arm 104, a pad conditioner head 107, a head carrier 106 configured to hold the pad conditioner head 107, a pad conditioner cylinder 108, or an oscillation component 105 between the pad conditioner arm 104 and the pad conditioner cylinder 108 that enables the pad conditioner cylinder 108 to oscillate the pad conditioner arm 104. In some embodiments, when the pad conditioner 102 is used to condition the polishing pad 120, at least one of the pad conditioner arm 104, the pad conditioner head 107 or the head carrier 106 overlie the polishing pad 120. In some embodiments, the pad conditioner head 107 is in contact with the polishing surface 121 of the polishing pad 120. In some embodiments, the pad conditioner 102 is configured to rotate at least one of the head carrier 106 or the pad conditioner head 107 in a third rotational direction 158. In some embodiments, the first rotational direction 154 and the third rotational direction 158 are the same rotational direction (e.g., clockwise or counterclockwise). Embodiments are contemplated in which the first rotational direction 154 and the third rotational direction 158 are different rotational directions (e.g., one is clockwise and the other is counterclockwise). In some embodiments, the pad conditioner head 107 is rotated using a third driving mechanism (not shown) of the pad conditioner 102, such as a motor configured to rotate the head carrier 106.

In some embodiments, the pad conditioner head 107 is configured to exert a first pad conditioning force onto the polishing pad 120. In some embodiments, the first pad conditioning force is exerted onto the polishing pad 120 in the direction 152 towards the polishing pad 120. In some embodiments, the first pad conditioning force is exerted onto the polishing pad 120 using a fourth driving mechanism (not shown) of the pad conditioner 102, such as a motor configured to move the pad conditioner head 107 in the (downwards) direction 152 and/or a (upwards) direction opposite to the direction 152. The first pad conditioning force is at least one of (i) between about 0 newtons to about 150 newtons, (ii) between about 2 newtons to about 110 newtons, or (iii) between about 1 newton to about 100 newtons. Other values of the first pad conditioning force are within the scope of the present disclosure. In some embodiments, the first pad conditioning force corresponds to a down force of the pad conditioner 102.

In some embodiments, the pad conditioner arm 104 is configured to oscillate the head carrier 106 and the pad conditioner head 107. In some embodiments, the pad conditioner arm 104 oscillates the head carrier 106 and the pad conditioner head 107 using a fifth driving mechanism (not shown) of the pad conditioner 102, such as a motor coupled to the pad conditioner cylinder 108.

In some embodiments, the pad conditioner head 107 performs a first conditioning process to condition at least a first portion of the polishing surface 121 of the polishing pad 120 in which at least one of (i) the pad conditioner head 107 is in contact with the polishing surface 121 of the polishing pad 120, (ii) the pad conditioner head 107 is rotated in the third rotational direction 158, or (iii) the pad conditioner head 107 is oscillated along a first oscillation path (not shown). In some embodiments, the first conditioning process at least one of (i) planarizes at least some of the first portion of the polishing surface 121 using the pad conditioner head 107, (ii) removes contaminants from the first portion of the polishing surface 121 using the pad conditioner head 107, wherein the contaminants comprise at least one of byproducts and/or residue from a semiconductor wafer polished using the polishing pad 120, or byproducts and/or residue from the slurry 134 provided by the slurry provider 122, (iii) removes defects from the first portion of the polishing surface 121 using the pad conditioner head 107, or (iv) removes a portion of the polishing pad 120 to adjust and/or reduce a thickness of at least a portion of the polishing pad 120.

In some embodiments, when the pad conditioner 102 is not being used to condition the polishing pad 120, at least one of the pad conditioner head 107 or the head carrier 106 rest in a resting position relative to a cleaning cup 114. In some embodiments, the cleaning cup 114 defines a chamber 117 in which a liquid 115 is stored. In some embodiments, the liquid 115 comprises at least one of water, deionized water, one or more cleaning chemicals, or one or more other suitable substances. In some embodiments, when the pad conditioner head 107 is in the resting position relative to the cleaning cup 114, at least one of (i) the pad conditioner head 107 is in contact with and/or submerged in the liquid 115, or (ii) at least a portion of the pad conditioner head 107 is in the chamber 117 defined by the cleaning cup 114.

FIG. 2 illustrates a perspective view of a liquid supply system 200, in accordance with some embodiments. The liquid supply system 200 can also be referred to as “the system 200.” The system 200 includes a base liquid supply sub-system 210, a mixing sub-system 220, an optional buffer sub-system 230, and a supply sub-system 240.

The base liquid supply sub-system 210 contains and supplies base liquid, which can be a base slurry. The base slurry can be contained in one or more first drums or “slurry drums” 212, 214. The base slurry can be supplied to the mixing sub-system 220 via a pump 216 that pumps the base slurry through a network of pipes that are in fluid communication with the mixing sub-system 220. Prior to entering the mixing sub-system 220, the base slurry is filtered by a filtration apparatus 218. The filtration apparatus 218, in operation, generates filtered base slurry by removing large particles from the base slurry, which is beneficial to improve yield of semiconductor wafers processed by one or more apparatuses that polish the semiconductor wafers using a polishing slurry that includes the filtered base slurry.

The base slurry can include a dispersion of polishing particles in a liquid. In some embodiments, the polishing particles or “abrasives” can include one or more of alumina, ceria, or silica (e.g., SiO₂, CeO₂, or the like) in one or more shapes and one or more sizes. In some embodiments, the size of the polishing particles is a diameter of the polishing particles, such as a maximum diameter of the polishing particles. In some embodiments, the polishing particles have sizes that are in a range of about 1 nanometer (nm) to about 100 nm, such as about 1 nm to about 10 nm, about 10 nm to about 20 nm, or another suitable range. The range of sizes can be selected to be beneficial for polishing a semiconductor wafer surface that has a material composition and feature depths. For example, shallower features may benefit from polishing particles of relatively larger sizes (e.g., about 10 nm to about 20 nm) whereas achieving a planar surface may benefit from polishing particles of sizes below about 10 nm.

The filtered base slurry exiting the filtration apparatus 218 has a reduced number of large particles therein than the base slurry that enters the filtration apparatus 218. The filtered base slurry that exits the filtration apparatus 218 is delivered to the mixing sub-system 220.

The mixing sub-system 220 includes one or more mixing drums or “mixing tanks” 221, 225 in which polishing slurry is formed, aged and stored prior to delivery to one or more of the buffer sub-system 230 and the supply sub-system 240. The mixing sub-system 220 may include one or more component tanks 222, 224, 226, 228 that can store various component materials and supply them to the mixing drums 221, 225, respectively. The component tanks 222, 226 may store and supply the filtered base slurry to the mixing drums 221, 225, respectively. The component tanks 224, 228 may store and supply deionized (DI) water to the mixing drums 221, 225, respectively. Additional component tanks may store and supply other component materials, such as pH adjusting additives, oxidizing additives (e.g., H₂O₂), dispersants, biocides, and the like. The mixing sub-system 220 introduces the filtered base slurry and other component materials into the mixing drums 221, 225. The filtered base slurry and the other components materials may form a mixture that is then agitated over a selected period of time referred to as “aging.” Polishing slurry may refer to the aged mixture. The polishing slurry may be transferred from the mixing drums 221, 225 to one or more of the buffer sub-system 230 and the supply sub-system 240. In some embodiments, a quality meter 229 is included in the mixing sub-system 220. The quality meter 229 can perform one or more tests on the mixture in the mixing drums 221, 225, which may include a pH test or other suitable test(s).

The buffer sub-system 230 may include one or more buffer tanks or drums 232, 234 that are in fluid communication with the mixing drums 221, 225. The buffer tanks 232, 234 may hold the polishing slurry received from the mixing sub-system 220 prior to delivering the polishing slurry to the supply sub-system 240. Pumps 236, 238 may be disposed to pump the polishing slurry out of the buffer tanks 232, 234, respectively, and into the supply sub-system 240. In some embodiments, the buffer sub-system 230 is not included, such that the supply sub-system 240 is in direct communication with the mixing drums 221, 225. Including the buffer tanks 232, 234 between the mixing drums 221, 225 and supply sub-system 240 in the system 200 can offer benefits. The mixing drums 221, 225 can experience variations in mixing intensity or time due to factors like batch size or operator technique. The buffer tanks 232, 234 provide a holding volume where the mixed slurry can undergo additional gentle mixing to improve homogeneity throughout the entire volume. This improves uniformity of distribution of abrasives, additives, and DI water throughout the final polishing slurry used in CMP. The withdrawal of mixture from the mixing drums 221, 225 can cause pulsations or flow rate variations. The buffer tanks 232, 234 can act as reservoirs, dampening the fluctuations and providing improved consistency in flow of the polishing slurry to the supply sub-system 240. Over time, denser abrasive particles in the slurry may settle slightly in the mixing drums 221, 225. The buffer tanks 232, 234 can provide additional holding volume to reduce the settling effect, which can improve consistency of concentration of abrasives throughout the polishing slurry and then during the CMP process. The buffer tanks 232, 234 can act as a buffer against temperature fluctuations that might occur in the mixing drums 221, 225. This can improve uniformity of temperature for the polishing slurry, which can be beneficial for factors like viscosity and dispersant effectiveness. Inclusion of two or more buffer tanks 232, 234 can provide additional flexibility in the system 200. For example, multiple mixing drums 221, 225 can be used to feed a single buffer tank (e.g., the buffer tank 232), allowing for continuous operation while one drum (e.g., the buffer tank 234) is refilled or cleaned.

The supply sub-system 240 is in fluid communication with the buffer sub-system 230 and receives the polishing slurry from the buffer sub-system 230. In some embodiments, the supply sub-system 240 includes one or more supply tanks or drums 242, 244. The supply tanks 242, 244 may hold the polishing slurry and may deliver the polishing slurry to one or more CMP apparatuses (e.g., the system 100) in fluid communication therewith. Pumps 246, 248 may be positioned to draw the polishing slurry out of the supply tanks 242, 244, respectively and to push the polishing slurry to the one or more CMP apparatuses.

In some embodiments, aging of the polishing slurry may occur in the buffer tanks 232, 234, the supply tanks 242, 244 or both. In embodiments in which the buffer tanks 232, 234 are present, fresh polishing slurry may be added from the mixing tanks 221, 225 to the buffer tanks 232, 234 when level of polishing slurry in the buffer tanks 232, 234 is below a refill level. In embodiments in which the buffer tanks 232, 234 are not present, the fresh polishing slurry may be added from the mixing tanks 221, 225 to the supply tanks 242, 244 when level of polishing slurry in the supply tanks 242, 244 is below a refill level.

FIG. 3 illustrates a schematic view of a supply tank 242 having a liquid level sensor assembly 350 thereon relative to other components of a polishing liquid supply system 300 (or “system 300”), in accordance with some embodiments. The system 300 may be an embodiment of the system 200 and may include substantially the same components as the system 200. The view of FIG. 3 may be simplified, such that one or more components of the polishing liquid supply system 300 are omitted from view. For example, a single mixing tank 221 and a single supply tank 242 that are in direct fluid communication with each other are depicted in the view of FIG. 3. In some embodiments, two or more mixing tanks are included, two or more supply tanks are included and optionally one, two or more buffer tanks (e.g., the buffer tanks 232, 234) are included in the system 300.

The system 300 includes a scale 320 that is under the mixing tank 221. In some embodiments, the scale 320 is or includes an industrial scale operable to weigh contents of the mixing tank 221. The industrial scale can also be referred to as a “tank scale.” The scale 320 may include one or more of the following components: (i) load cells, (ii) weigh modules or (iii) an indicator/controller. The load cells may be or include high-precision sensors placed at selected positions under a support structure of the mixing tank 221. When the mixing tank 221 is filled or one or more slurry components (e.g., base slurry, DI water, additives) are added thereto, the resulting weight applies pressure to the load cells, causing them to deform slightly. This deformation is converted into an electrical signal. The load cells can be or include high-strength materials like steel or stainless steel to handle heavy loads and harsh industrial environments. The weigh modules are platforms that can house multiple load cells and provide a stable base for the mixing tank 221. The weigh modules can simplify installation and improve load distribution across the cells. The indicator/controller is a user interface that displays weight of contents of the mixing tank 221 based on the electrical signal from the load cells. The indicator/controller can be a simple display or a more advanced system that integrates with process control software for automated filling or monitoring. In some embodiments, the scale 320 is operable to perform “gain-in-weight” and/or “loss-in-weight” applications. In gain-in-weight, the weight increase indicates the amount of material added to the mixing tank 221. In loss-in-weight, amount dispensed from the mixing tank 221 is measured. The scale 320 is in electrical communication with a controller 360, which is described in greater detail below. The scale 320 is operable to generate weight data associated with the slurry 134 in the supply tank 242 and to transmit the weight data to the controller 360 electronically. The controller 360 may also be referred to as a programmable logic controller or “PLC” 360.

The system 300 includes one or more pumps 330 operable to supply mixed slurry from the mixing tank 221 to the supply tank 242 or optionally to the buffer tank 232, for example. The pump 330 may be positioned under the mixing tank 221 between the mixing tank 221 and the scale 320 and may be in fluid communication with the mixing tank 221 and the supply tank 242 or optionally the buffer tank 232. For transferring slurry from the mixing tank 221 to a buffer tank 232 or supply tank 242 in the systems 200, 300, various pump types can be suitable depending on characteristics of the slurry. In some embodiments, the pump 330 is or includes a positive displacement (PD) pump that is operable to trap a selected volume of slurry within a chamber and then force it out using a moving part like a piston, diaphragm, or gear. PD pumps can be beneficial for handling viscous and shear-sensitive slurries and can maintain a consistent flow rate regardless of discharge pressure variations. The enclosed design can reduce air entrainment, which is beneficial for CMP slurries where air bubbles can affect polishing uniformity. The PD pump can be or include a peristaltic pump, diaphragm pump, gear pump, or the like. In some embodiments, the pump 330 is or includes a centrifugal pump that uses a rotating impeller to generate centrifugal force that accelerates the slurry outwards from the center of the pump housing. The centrifugal pump can offer a high flow rate and may be less expensive than a PD pump.

The system 300 includes one or more pumps 340, which can include a first pump 342, a second pump 344, or both. The pumps 340 are operable to transport polishing slurry from the supply tank 242 to a valve manifold box 380. The pumps 340 may be any of the pumps just described as embodiments of the pump 330. The pumps 340 are in fluid communication with the supply tank 242 and the valve manifold box 380.

The system 300 includes a continuous liquid level sensor assembly 350, which can include a first set of sensors 352 and a second set of sensors 354. The first set of sensors 352 and the second set of sensors 354 can be referred to collectively as the sets 352, 354. The first set of sensors 352, or simply “the set 352,” is described in detail. The second set of sensors 354 is substantially the same or the same as the set 352 and details thereof are not described to avoid repetition. In some embodiments, the liquid level sensor assembly 350 extends continuously from a first end 243 of the supply tank 242 to a second end 245 of the supply tank 242.

In some embodiments, the set 352 includes one or more capacitive liquid level sensors that utilize capacitance to detect presence or level of liquid (e.g., the slurry 134) in a tank (e.g., the buffer tank 232 or the supply tank 242). The capacitive liquid level sensor can include two electrodes separated by a dielectric material (usually air). The electrodes can be implemented in various forms, such as plate electrodes, coaxial electrodes, printed circuit board (PCB) traces or the like. Capacitance between the electrodes is directly proportional to permittivity of material between them. Air, for example, has a much lower permittivity compared to most liquids. In operation, when the supply tank 242 is empty, the dielectric between the electrodes is air, resulting in a low capacitance value. As liquid (e.g., the slurry 134) fills the tank and covers the electrodes (or a portion of them for level sensing), the permittivity of the space between the electrodes increases due to the presence of the liquid. This, in turn, causes the capacitance to increase. In some embodiments, the liquid level sensor assembly 350 includes a number of capacitive liquid level sensors that are arranged along at different levels along a vertical axis of the supply tank 242. In some embodiments, the number of capacitive liquid level sensors is at least three, at least 10, at least 20, at least 50, at least 100 or another suitable number. Having at least twenty capacitive liquid level sensors is beneficial to allow control of a refill line at a resolution of about 5% of volume of polishing slurry in the supply tank 242. In some embodiments, resolution of the liquid level sensor assembly 350 is in a range of about 1% to about 20%, such as about 5% to about 10%. In some embodiments, the resolution is finer than about 33%, finer than about 30%, finer than about 25%, finer than about 10% or finer than about 5%. Other ranges for the resolution that are between or included in the stated ranges are also contemplated in embodiments herein.

Although the above description of the set 352 is given for capacitive liquid level sensors, the set 352 is not limited thereto. In some embodiments, the set 352 is or includes one or more ultrasonic level sensors that can emit high-frequency sound waves towards the surface of the slurry 134 in the tank 242 and measure time for the sound waves to travel back. In some embodiments, the set 352 is or includes one or more radar level sensors that can emit electromagnetic waves (e.g., microwaves) towards the liquid surface. The reflected wave is used to calculate presence of the liquid and determine the level. In some embodiments, the set 352 is or includes one or more optical level sensors that can emit light beams (e.g., infrared or laser) to detect the presence or level of liquid.

The sensor electronics can measure the capacitance and convert it to an electrical signal indicating the presence or level of the liquid. The electrical signal can be (i) binary, indicating simply whether liquid is present or not (e.g., for basic presence detection) or (ii) analog, varying continuously with the liquid level (e.g., for precise level measurement). The capacitive liquid level sensors are non-contact, meaning they do not make direct contact with the slurry 134. As depicted, the set 352 may be mounted to an outer sidewall of a housing of the supply tank 242. The set 352 and the set 354 are in electrical communication with the controller 360 and are operable to transmit liquid presence data, liquid level data, or both to the controller 360. In some embodiments, the sets 352, 354 are in electrical communication and/or data communication with the controller 360 via a network apparatus 370, which can be a wired or wireless network apparatus.

The system 300 includes the controller 360, which is a programmable logic controller (PLC), in some embodiments. The controller 360, or PLC 360, can be an industrial computer operable to perform automation tasks. The controller 360 can control various automated processes in a factory in which the polishing system 100 and/or the liquid supply system 200, 300 is located. The controller 360 can receive input signals from sensors and switches, such as the scale 320 and the liquid level sensor assembly 350, process the input signals based on processor-executable instructions, then generate output signals to control machines, valves, motors, other actuators, and the like. The controller 360 may be modular, allowing for easy customization. For example, input/output (I/O) modules may be added or removed to accommodate selected functions of an application, such as slurry mixing, aging and delivery. Modules or electrical components of the controller 360 can include input modules or components, output modules or components, processing modules or processors, memory or memory circuitry, computer-readable processor-executable instructions stored in the memory, and the like. In some embodiments, the controller 360 can perform data logging and monitoring of process variables, such as the weight data, the presence and/or level data, and the like.

Although not separately illustrated, the system 300 may include one or more conductivity sensors in each of the mixing tanks 221, 225, the buffer tanks 232, 234 and the supply tanks 242, 244. The conductivity sensors may be in data communication with the controller 360. Each of the conductivity sensors may be in contact with the polishing slurry in the respective tank 221, 225, 232, 234, 242, 244 for generating conductivity data associated with the polishing slurry (e.g., conductivity of the polishing slurry) in each of the tanks 221, 225, 232, 234, 242, 244. The conductivity data may include conductivity values that have units of siemens per meter (S/m) or another suitable unit of measurement.

The system 300 includes the network apparatus 370, which may also be referred to as an input/output (I/O) controller 370 or “I/O master 370,” in some embodiments. In some embodiments, the I/O master 370 operates via Ethernet and/or internet protocol (IP) and is a device that operates as a central hub for managing input/output (I/O) signals over an Ethernet network using the Internet Protocol (IP). The I/O master 370 can connect to various remote I/O modules (slaves) distributed across the network. In some embodiments, the modules handle actual physical connections to sensors and actuators, such as the liquid level sensor assembly 350 and the scale 320. The I/O master 370 communicates with the slave modules, collecting input data from sensors and sending control signals to actuators, for example. In some embodiments, the I/O master 370 utilizes the Ethernet network infrastructure for communication. Ethernet provides a reliable and standardized way to connect devices. IP (Internet Protocol) addresses are used to uniquely identify each device on the network, allowing the I/O master 370 to specifically target individual I/O modules. In some embodiments, the I/O master 370 is accessed and configured remotely from a computer on the network. In some embodiments, the I/O master 370 is an embedded I/O master that is integrated within a larger control system, such as the PLC 360. The PLC 360 can act as a central control unit and the embedded I/O master 370 can handle communication with remote I/O modules. In some embodiments, the I/O master 370 is a stand-alone I/O master that is a dedicated device for I/O communication over Ethernet. The I/O master 370 is in data communication with the PLC 360 and the liquid level sensor assembly 350. In some embodiments, the I/O master 370 is in data communication with the scale 320.

The system 300 includes a valve manifold box (VMB) 380 that is in fluid communication with the pumps 340 and the supply tank 242. Although not specifically depicted in FIG. 3, the VMB 380 is in fluid communication with the polishing system 100 to deliver polishing slurry 134 from the supply tank 242 to the polishing apparatus 160.

In some embodiments, the VMB 380 operates as a central hub for managing distribution and control of the polishing slurry 134 contained in the supply tank 242. The VMB 380 can house multiple valves within a single enclosed box. These valves are connected to a single source of gas or fluid, such as the supply tank 242, and each valve controls flow of the polishing slurry 134 to a separate destination (e.g., a first CMP tool, a second CMP tool, and the like). This allows for efficient control and distribution from one source (e.g., the supply tank 242) to various locations. In some embodiments, the VMB 380 is configured for integration with production equipment, such as in a cleanroom environment. In some embodiments, the VMB 380 is a multi-source VMB that can accommodate multiple sources (e.g., the supply tanks 242, 244 or a slurry supply and another material supply) and distribute the multiple sources to different destinations. In some embodiments, the VMB 380 is in data communication with the controller 360 optionally via the I/O controller 370 and can send and receive data and commands to and from the controller 360. In some embodiments, the VMB 380 is in data communication with a controller other than the controller 360 for receiving commands, such as whether to open or close one or more valves therein to enable or disable delivery of polishing slurry to one or more CMP tools, such as the polishing apparatus 160.

FIG. 4A illustrates a method of adjusting refill level and mix-in volume of a polishing liquid supply system, in accordance with some embodiments. FIG. 4B illustrates a method of adjusting refill level and mix-in volume of a polishing liquid supply system, in accordance with some embodiments. FIG. 8 illustrates a method 800 that is an embodiment of the methods depicted in flowchart form. Reference to operations of FIG. 8 will be given in description of the methods or processes depicted in FIGS. 4A and 4B.

FIG. 4A illustrates process 400 in which a higher production volume mode is entered from a lower production volume mode. The process 400 is described with reference to the supply tank 242, but may be used with the supply tank 244, the buffer tank(s) 232, 234 or other tanks used for storing and supplying a liquid to processing equipment.

At operation 401 and operation 802, the supply tank 242 includes a base polishing slurry volume 410 and a consumption polishing slurry volume 420. The base polishing slurry volume 410 is a volume of polishing slurry that is at and/or below a first refill line or level 412. The first refill line 412 is associated with a level of the liquid level sensor assembly 350. In some embodiments, the first refill line 412 is associated with a value, such as a height measured in centimeters, meters, inches, or the like. The height may be measured from a bottom of a storage volume of the supply tank 242, a bottom of the liquid level sensor assembly 350, or the like. In some embodiments, the first refill line 412 is associated with a percentage, such as 10%, 20%, 50%, or the like. The percentage may be a percentage of height of the liquid level sensor assembly 350, a percentage of volume of the storage volume of the supply tank 242, or the like. The level of the liquid level sensor assembly 350 may be associated with a volume of polishing slurry contained by the supply tank 242, such as a number of liters, gallons, or the like. The first refill line 412 may be a level of the liquid level sensor assembly 350 that operates as a threshold value below which fresh polishing slurry is added to the supply tank 242, for example, from the mixing tank 221. When the base polishing slurry volume 410 has volume below the threshold value, the fresh polishing slurry may be added such that overall volume of polishing slurry in the supply tank 242 may be at or above the first refill line 412. In the process 400, the first refill line 412 may be at a relatively low level, such as about 40%, 30%, 25%, 20% or lower.

The consumption polishing slurry volume 420 is a volume of the polishing slurry that is scheduled for consumption (e.g., delivery) to one or more polishing apparatuses, such as the polishing apparatus 160. For example, volume of the consumption polishing slurry volume 420 may be based on a forecasted slurry consumption value which is determined in operation 804 of method 800. The forecasted slurry consumption value may be a volume of polishing slurry that is determined to be consumed by one or more polishing apparatuses (e.g., the polishing apparatus 160) over a selected time interval, such as a number of hours (e.g., 8 hours, 12 hours, etc.) or days (e.g., 1 day, 1.5 days, etc.). The determination may be based on a number of wafers or wafer batches to be processed by the polishing apparatus(es) over the selected time interval. The determination may take into account removal rate associated with the polishing slurry, which may be based on aging time of the polishing slurry. For example, a reduced removal rate as a result of aging over time may result in increased consumption of polishing slurry.

At operation 402, the consumption polishing slurry volume 420 is entirely consumed and level of the base polishing slurry volume 410 is at or near (e.g., slightly below) the first refill line 412. In some embodiments, operation 402 precedes operation 403. In some embodiments, operation 403 may be performed prior to the consumption polishing slurry volume 420 being entirely consumed.

At operation 403, at least one of (i) the first refill line 412 or (ii) a mix-in fresh polishing slurry volume 430 (or simply “mix-in polishing slurry volume 430”) is adjusted in accordance with the forecasted slurry consumption value. As depicted in FIG. 8, a determination may be made whether the forecasted slurry consumption value has increased or decreased in operation 806. The determination in operation 806 may be a simple comparison between a current forecasted slurry consumption value (or “current value”) and a new forecasted slurry consumption value (or “new value”). When the new value exceeds the current value, the determination is that the forecasted slurry consumption value has increased. When the new value is less than the current value, the determination is that the forecasted slurry consumption value has decreased. In some embodiments, the determination may be conditional on a threshold value, such that “increased” is only determined when the difference between the new value and the current value exceeds the threshold value. Such an algorithm can result in fewer adjustments to the refill line, the mix-in volume, or both. In response to the determination in operation 806 being that the forecasted slurry consumption value increased, the method 800 can proceed to operations 808 and 812. In response to the determination in operation 806 being that the forecasted slurry consumption value decreased, the method 800 can proceed to operations 810, 814, and optionally 816.

In the example of FIG. 4A, in a high production mode, the forecasted slurry consumption value may increase. As such, the first refill line 412 may be increased to a second refill line or “high refill line” 412H, corresponding to operation 812 of FIG. 8. The second refill line 412H is at a higher level of the liquid level sensor assembly 350 than the first refill line 412. For example, the first refill line 412 may be at 25% and the second refill line 412H may be at 50%. Selecting the second refill line 412H instead of the first refill line 412 increases volume of the base polishing slurry volume 410, such that a larger volume of the polishing slurry is held in reserve to buffer against higher consumption during the high production mode.

Further in operation 403, in accordance with some embodiments, the mix-in fresh polishing slurry volume 430 may be increased, corresponding to operation 808 of FIG. 8. For example, prior to operation 403, a first volume of the mix-in fresh polishing slurry volume 430 may be selected as 100 liters (L), then during operation 403, the first volume may be replaced by a second volume of the mix-in fresh polishing slurry volume 430, which may be selected as 150 L, 200 L, or another suitable value. In some embodiments, the volume of the mix-in fresh polishing slurry volume 430 may be a percentage of volume of the slurry-holding portion of the supply tank 242, such as 10%, 20%, 25%, 50%, or another suitable percentage. The second volume exceeds the first volume when the forecasted slurry consumption value is increased.

In FIG. 8, following operations 808 and 812, the method 800 may return to operation 804 to determine the forecasted polishing slurry consumption. In some embodiments, operation 804 is performed continuously. Namely, operation 804 may be performed during one or more of operations 806, 808, 812, 810, 814 and 816.

In operation 404, polishing slurry in the supply tank 242 is aged, resulting in the base polishing slurry volume 410 and the consumption polishing slurry volume 420. Operation 404 depicts that, following mixing in of the mix-in fresh polishing slurry volume 430 and aging, the base polishing slurry volume 410 increases from the first refill line 412 to the second refill line 412H and the consumption polishing slurry volume 420 is a volume of the polishing slurry in excess of the base polishing slurry volume 410.

At operation 405, the consumption polishing slurry volume 420 is entirely consumed, at which point a signal may be generated to which the controller 360 can control the system 300 to mix in additional fresh slurry to the supply tank 242.

At operation 406, the mix-in fresh polishing slurry volume 430 is added to the supply tank 242 according to the second volume.

FIG. 4B illustrates process 450 in which a lower production volume mode is entered from a higher production volume mode. The process 450 is described with reference to the supply tank 242, but may be used with the supply tank 244, the buffer tank(s) 232, 234 or other tanks used for storing and supplying a liquid to processing equipment. The process 450 is similar to the process 400 in some respects and some description of similar concepts therebetween may be omitted for brevity.

At operation 451, the first refill line 412 is at a relatively high level, such as about 30%, 40%, and 50% or higher. Because the lower production volume mode is entered from the higher production volume mode, the polishing slurry above the first refill line 412 may include the consumption polishing slurry volume 420 and a dump polishing slurry volume 440. Namely, entirely consuming the consumption polishing slurry volume 420 may be insufficient to bring overall level of polishing slurry in the supply tank 242 below the first refill line 412 prior to aging past an acceptable quality threshold or useful lifetime. As such, the dump polishing slurry volume 440 is a volume of the polishing slurry that is scheduled to be removed from the supply tank 242 to bring the volume of polishing slurry in the supply tank 242 down to at or near the first refill line 412. Removing the dump polishing slurry volume 440 results in waste and added cost. As such, in the process 450, the first refill line 412 is replaced with a lower second refill line 412L and a first volume of the mix-in polishing slurry volume 430 is replaced with a lower second volume of the mix-in polishing slurry volume 430.

At operation 452, following consumption of the consumption polishing slurry volume 420 and removal of the dump polishing slurry volume 440, the level of the polishing slurry in the supply tank 242 is at or near the first refill line 412. In some embodiments, operation 452 is optional and operation 453 may be performed prior to the consumption polishing slurry volume 420 being consumed entirely and prior to the dump polishing slurry volume 440 being removed.

At operation 453, in response to the forecasted slurry consumption value being reduced, the first refill line 412 is replaced with the lower second refill line 412L, corresponding to operation 814 of FIG. 8. For example, the first refill line 412 may be about 50% and the second refill line 412L may be about 25%. Other percentages or discrete values for the first and second refill lines 412, 412L are contemplated as embodiments herein. Generally, in response to the forecasted slurry consumption value being reduced, the second refill line 412L has value that is lower than that of the first refill line 412.

In operation 453, the first volume of the mix-in polishing slurry volume 430 is replaced with the lower second volume, corresponding to operation 810 of FIG. 8. For example, the first volume may be about 150 L, 200 L, or more and the second volume may be about 100 L, 50 L, or less. Generally, in response to the forecasted slurry consumption value being reduced, the second volume has value that is lower than that of the first volume.

At operation 454, polishing slurry in the supply tank 242 is aged, resulting in the base polishing slurry volume 410 and the consumption polishing slurry volume 420. In some embodiments, a small amount of the dump polishing slurry volume 440 is generated in the supply tank 242, which may be removed corresponding to operation 816 of FIG. 8. Operation 404 depicts that, following mixing in of the mix-in fresh polishing slurry volume 430 and aging, the base polishing slurry volume 410 decreases from the first refill line 412 to the second refill line 412L and the consumption polishing slurry volume 420 is a volume of the polishing slurry in excess of the base polishing slurry volume 410. Due to adding the smaller second volume of the mix-in polishing slurry volume 430 instead of the larger first volume, less or no dump polishing slurry volume 440 is generated in the supply tank 242, resulting in a reduction in waste and cost.

At operation 455, following consumption of the consumption polishing slurry volume 420 and optional removal of the dump polishing slurry volume 440 in operation 816 of FIG. 8 (if needed), the polishing slurry in the supply tank 242 is at or near the second refill line 412L. In response to this, a signal may be generated to which the controller 360 can control the system 300 to mix in additional fresh slurry to the supply tank 242 using the lower second volume.

At operation 456, the mix-in fresh polishing slurry volume 430 is added to the supply tank 242 according to the second volume.

In some embodiments, the processes 400 and 450 may be combined. For example, following increasing the refill line from the first refill line 412 to the second refill line 412H in the process 400, the refill line may be reduced from the second refill line 412H to the second refill line 412L in the process 450. In another example, following reducing the refill line from the first refill line 412 to the second refill line 412L in the process 450, the refill line may be increased from the second refill line 412L to the second refill line 412H in the process 400. In yet another example, the first volume may be increased to the second volume in the process 400, then the second volume may be decreased to another lower volume in the process 450. Combining the processes 400, 450 can result in a process that dynamically adjusts the refill line, the mix-in volume or both based on variations in the forecasted slurry consumption value.

FIG. 5 illustrates a schematic view of a slurry delivery monitoring system (shown with reference number 500), according to some embodiments. The slurry delivery monitoring system 500 comprises at least one of a set of tank monitoring devices 504, facility equipment 502 of a facility, a computer 514, a tank status system 506, or one or more client devices 508. The set of tank monitoring devices 504 comprises tank monitoring devices distributed at various locations of the facility. The tank monitoring devices are used to determine measurements associated with tanks and/or other equipment in the facility, such as the tanks 221, 225, 232, 234, 242, 244 described with reference to FIGS. 2 and 3.

In some embodiments, the set of tank monitoring devices 504 transmit a set of monitoring signals 512 to the computer 514. In some embodiments, each signal of the set of monitoring signals 512 is transmitted by a monitoring device, of the set of tank monitoring devices 504, in a polishing apparatus of the facility. In some embodiments, the set of tank monitoring devices 504 comprises at least one of a first set of monitoring devices for the system 300, a second set of monitoring devices for a second polishing liquid supply system, etc. In some embodiments, the first set of tank monitoring devices 504 comprises at least one of the scale 320, the liquid level sensor assembly 350, the conductivity sensor(s), or one or more other monitoring devices.

In some embodiments, the set of monitoring signals 512 comprises a first monitoring signal from the liquid level sensor assembly 350. In some embodiments, the liquid level sensor assembly 350 comprises a wireless communication module that transmits the first monitoring signal to the computer 514 wirelessly. In some embodiments, the liquid level sensor assembly 350 transmits the first monitoring signal to the computer 514 over a wired connection between the liquid level sensor assembly 350 and the computer 514. In some embodiments, the first monitoring signal is indicative of the level of polishing slurry associated with the supply tank 242.

In some embodiments, the set of monitoring signals 512 comprises a second monitoring signal from the conductivity sensor in the supply tank 242. In some embodiments, the conductivity sensor comprises a wireless communication module that transmits the second monitoring signal to the computer 514 wirelessly. In some embodiments, the conductivity sensor transmits the second monitoring signal to the computer 514 over a wired connection between the conductivity sensor and the computer 514. In some embodiments, the second monitoring signal is indicative of the conductivity of the polishing slurry in the supply tank 242.

In some embodiments, the computer 514 controls a display panel 520 comprising a set of status indicators associated with tanks in the facility. In some embodiments, an indicator of the set of status indicators comprises a light, such as an indicator light, that indicates whether a corresponding tank is associated with a change in refill line, a change in mix-in volume, or both, wherein the light being in a first state indicates that the corresponding tank is associated with the change and/or the light being in a second state indicates that the corresponding polishing apparatus is not associated with the change. In some embodiments, the display panel 520 comprises a display configured to display an alert indicative of one or more detected potential statuses of one or more tanks. In some embodiments, the first state corresponds to a first color emitted by the light, such as red or other color, and the second state corresponds to a second color emitted by the light, such as green or other color. The set of status indicators comprises at least one of a first indicator “TNK1” associated with a first tank (e.g., the supply tank 242), a second indicator “TNK2” associated with a second tank (e.g., the mixing tank 221), a third indicator “TNK3” associated with a third tank (e.g., the buffer tank 232), a fourth indicator “TNK4” associated with a fourth tank, or other indicator.

In some embodiments, the computer 514 provides one or more first signals 510 to the facility equipment 502. In some embodiments, the one or more first signals 510 are used to control at least some of the facility equipment 502, such as one, some or all base slurry supply systems of the facility and/or other equipment of the facility. In some embodiments, the one or more first signals 510 are generated using a signal generator of the computer 514. The one or more first signals 510 are indicative of at least one of (i) an updated refill line, (ii) an updated mix-in volume, or (iii) other information. In some embodiments, the computer 514 transmits the one or more first signals 510 to the facility equipment 502 wirelessly, such as using a wireless communication device of the computer 514. In some embodiments, the computer 514 transmits the one or more first signals 510 to the facility equipment 502 over a physical connection between the computer 514 and the facility equipment 502. In some embodiments, the computer 514 transmits the one or more first signals 510 to the controller 360 that controls refill line of the liquid level sensor assembly 350 and mix-in volume of the mixing sub-system 220.

In some embodiments, the computer 514 transmits a second signal 518 to the tank status system 506. The second signal 518 is generated using the signal generator of the computer 514. In some embodiments, the second signal 518 is indicative of at least one of (i) the set of tank statuses, (ii) the list of tanks that are determined to be associated with a change in refill line and/or mix-in volume, or (iii) other information. In some embodiments, the computer 514 transmits the second signal 518 to the tank status system 506 wirelessly, such as using the wireless communication device of the computer 514. In some embodiments, the computer 514 transmits the second signal 518 to the tank status system 506 over a physical connection between the computer 514 and the tank status system 506. In some embodiments, the tank status system 506 triggers an alarm function based upon the second signal 518. In some embodiments, the tank status system 506 triggers the alarm function based upon the second signal 518 indicating that the tank is associated with a halt in production due to the refill line and/or the mix-in volume being too low. In some embodiments, in response to triggering the alarm function, an alarm message is displayed via a display of the tank status system 506. The alarm message comprises at least one of an indication that the tank is associated with the halt in production, an indication of lead time to remedy the halt, an indication comprising an instruction for the tank to cease operating (until the base polishing slurry level is sufficiently high, for example), or other indication. In some embodiments, an alarm sound is output via a speaker connected to the tank status system 506 in response to triggering the alarm function.

In some embodiments, the computer 514 transmits a third signal 516 to one or more client devices 508. The one or more client devices 508 comprise at least one of a phone, a smartphone, a mobile phone, a landline, a laptop, a desktop computer, hardware, or other type of client device. The third signal 516 is generated using the signal generator of the computer 514. In some embodiments, the third signal 516 is indicative of at least one of (i) the set of tank apparatus statuses, (ii) the list of tanks that are determined to be associated with a change or a halt, or (iii) other information. In some embodiments, the computer 514 transmits the third signal 516 to a client device of the one or more client devices 508 wirelessly, such as using the wireless communication device of the computer 514. In some embodiments, the computer 514 transmits the third signal 516 to a client device of the one or more client devices 508 over a physical connection between the computer 514 and the client device. In some embodiments, the third signal 516 comprises a message, such as at least one of an email, a text message, etc., transmitted in response to detecting one or more changes or halts associated with one or more tanks, such as the change in refill line associated with the supply tank 242. In some embodiments, in response to detecting a change in refill line associated with a tank, a telephonic call is made to a client device, such as a landline or a mobile phone, of the one or more client devices 508, such as using a dialer of the computer 514.

In some embodiments, the set of monitoring signals 512 are used as feedback based upon which operation of the facility equipment 502 is controlled by the computer 514. In some embodiments, the computer 514 controls operation of the facility equipment 502 based upon measurements provided by the set of monitoring signals 512. In some embodiments, operation of the facility equipment 502 is controlled using the one or more first signals 510. In some embodiments, a signal of the one or more first signals 510 is indicative of one or more instructions.

In some embodiments, the supply tank 242 of the facility equipment 502 at least one of ceases operation, enters a locked state, or performs another operation in response to receiving a signal (of the one or more first signals 510) at least one of (i) indicating that the level of polishing slurry is less than a forecasted slurry consumption value or (ii) indicating an instruction to cease operation, enter the locked state, or perform another operation. In some embodiments, the one or more first signals 510 comprise a signal transmitted to a machine, such as the supply sub-system 240. In some embodiments, the signal instructs the machine to engage the supply tank 244 while the supply tank 242 is undergoing mixing and aging of polishing slurry. In some embodiments, the signal allocates one or more resources (e.g., manpower, a robot, one or more tools, the replacement component, etc.) to the supply tank 242 to be used for remedying the halt associated with the supply tank 242.

In some embodiments, in response to determining that the supply tank 242 is not associated with a halt, the supply tank 242 is used to supply polishing slurry to the polishing apparatus, so as to perform a polishing process on the first semiconductor wafer 132. In some embodiments, in response to determining that the supply tank 242 is associated with the halt, the computer 514 instructs the supply tank 242 to not deliver the polishing slurry (until the halt is addressed, for example). During the polishing liquid supply system 200 not delivering the polishing slurry via the supply tank 242, the polishing liquid supply system 200 may deliver the base slurry via another supply tank, such as the supply tank 244. In some embodiments, during the polishing liquid supply system 200 not delivering the polishing slurry via the supply tank 242, the polishing liquid supply system 200 may continue delivery of the polishing slurry without stopping polishing of the first semiconductor wafer 132 on the basis that sufficient aged slurry is present in one or more of the buffer tanks 232, 234, the supply tank 244, or both.

FIG. 6A illustrates a schematic view of a scenario 600 in which a computer determines polishing liquid supply parameters 610 associated with a polishing liquid supply system 300, in accordance with some embodiments. In some embodiments, the computer 514 determines the polishing liquid supply parameters 610 based upon at least one of (i) polishing liquid data (shown with reference number 602) associated with the polishing slurry, (ii) tool data (shown with reference number 604) associated with the polishing apparatus(es) 160, or (iii) wafer production data (shown with reference number 606) associated with a manufacturing facility in which the polishing apparatus(es) 160 reside. In some embodiments, the computer 514 performs one or more processing operations to determine the polishing liquid supply parameters 610. In some examples, the polishing liquid supply parameters 610 are indicative of the refill line, the mix-in volume, or both.

FIG. 6B illustrates one example embodiment of the scenario 600 (labeled with reference number 650). In the embodiment depicted in FIG. 6B, a mix-in volume and refill level determination system 656 and a manufacturing scheduling system 658 each receive mean residence time (MRT) and conductivity data 652 and production flow data 654. The mix-in volume and refill level determination system 656 may determine mix-in volume and refill level based on the MRT and conductivity data 652 associated with the polishing slurry in the supply tank 242 and based on the production flow data 654 associated with volume of wafers scheduled to be polished by the polishing apparatus(es) 160. For example, the mix-in volume and refill level determination system 656 may determine the forecasted slurry consumption value based on the volume of wafers scheduled to be polished, MRT of the polishing slurry in the second tank 242 and conductivity of the polishing slurry in the second tank 242. Namely, the MRT and conductivity may be related to removal rate and thereby volume of polishing slurry that will be consumed to polish the volume of wafers indicated by the production flow data 654. The removal rate and volume of wafers may be the basis for determining the forecasted slurry consumption value.

Based on the forecasted slurry consumption value, the mix-in volume and refill level determination system 656 may determine the mix-in volume and the refill level for the supply tank 242. For example, when the forecasted slurry consumption value is a first value, the mix-in volume and refill level determination system 656 may determine the mix-in volume and the refill level as the first mix-in volume and the first refill level. When the forecasted slurry consumption value is a second value, the mix-in volume and refill level determination system 656 may determine the mix-in volume and the refill level as the second mix-in volume and the second refill level that are different than the first mix-in volume and the first refill level. In some embodiments, the determination is based on a lookup table that associates the forecasted slurry consumption value with a refill level and a mix-in volume. In some embodiments, the determination is based on a calculation algorithm by which the forecasted slurry consumption value is calculated using, for example, a linear relationship, polynomial relationship, exponential relationship, or other appropriate relationship between the forecasted slurry consumption value and the refill level and mix-in volume. In some embodiments, the refill level is determined relative to the current refill level based on the forecasted slurry consumption value. For example, the refill level may be selected as a percentage (e.g., 110%, 50%, etc.) of the current refill level based on the forecasted slurry consumption value. In another example, the refill level may be determined as a discrete value (e.g., 50 L, 100 L, etc.) more or less than the current refill level based on the forecasted slurry consumption value.

The mix-in volume and refill level determination system 656 may generate a refill level or “refill line” and a mix-in volume as just described, and may output the refill level and mix-in volume to an intelligent slurry delivery system 660. The intelligent slurry delivery system 660 may be an embodiment of the systems 200, 300 described with reference to FIGS. 2-5, 8. For example, the controller 360 may receive the refill level and the mix-in volume, store the refill level and mix-in volume in memory thereof, and use the refill level to determine when to trigger refill of the supply tank 242 and determine how much fresh polishing slurry to add to the supply tank 242 based the mix-in volume.

The manufacturing scheduling system 658 may schedule delivery of polishing slurry from the supply tank 242 based on the MRT and conductivity data 652 and the production flow data 654. For example, the MRT and conductivity data 652 may inform the manufacturing scheduling system 658 about aging progress of the polishing slurry in the supply tank 242 and may be a basis for determining whether and/or how much polishing slurry is to be delivered from the supply tank 242 to the polishing apparatus(es) 160. In another example, the production flow data 654 may be utilized in coordination with liquid level of the supply tank 242 to determine the consumption polishing slurry volume 420 of the supply tank 242 that is to be delivered to the polishing apparatus(es) 160.

In some embodiments, the computer 514 uses one or more machine learning models utilizing artificial intelligence to determine the polishing liquid supply parameters 610. FIGS. 7A and 7B illustrate schematic views of a machine learning model system 700 training machine learning models and using trained machine learning models to evaluate data obtained using one or more devices of the set of tank monitoring devices 504 and other data, in accordance with some embodiments. FIG. 7A illustrates using a training module 718 to train a machine learning model to generate a first trained machine learning model or “slurry supply model” 720. In some embodiments, the training module 718 trains the machine learning model to generate the trained machine learning model 720 using at least one of polishing liquid historical data 702, tool historical data 704 or wafer production historical data 706, each of which may include labeled training data. In some embodiments, the polishing liquid historical data 702 comprises historical values associated with polishing slurry stored in one or more of the tanks 221, 225, 232, 234, 242, 244, such as mixing tank, buffer tank and/or supply tank polishing slurry conductivity data, mix-in volume data, polishing slurry conductivity increase rate data, refill time, supply lifetime and the like. The supply lifetime may be historical data calculated based on the refill line and mix-in volume. For example, a timer may be started when the polishing slurry reaches the refill line and fresh polishing slurry is mixed in according to the mix-in volume (e.g., the timer may start once the entire mix-in volume of fresh polishing slurry is finished being added to the supply tank 242). Then, the timer may run continuously while the polishing slurry is consumed by the polishing apparatus(es) 160. The timer may be stopped when the refill line is reached again. The supply lifetime can be a measure of time that has elapsed from the time the timer began to the time the timer ended as just described.

In some embodiments, the tool historical data 704 comprises historical values associated with use of the polishing slurry by the polishing apparatus(es) 160, such as number of polishing apparatus(es) 160 supplied by the liquid supply system 300, consumption of polishing slurry by each of the polishing apparatus(es) 160 and the like.

In some embodiments, the wafer production historical data 706 comprises historical values associated with processing of wafers by the polishing apparatus(es) 160, such as total number of wafers polished by the polishing apparatus(es) 160, daily number of wafers polished by the polishing apparatus(es) 160, number of wafers polished by each individual polishing apparatus 160 and the like.

In some embodiments, labeled data in the polishing liquid historical data 702, the tool historical data 704 or the wafer production historical data 706 is indicative of how training data results in removal rate, slurry consumption rate or the like.

In some embodiments, the trained machine learning model 720 is trained to perform a processing task associated with determining a forecasted slurry consumption value. In some embodiments, the processing task comprises evaluating a number of wafers to be polished, such as a daily number of wafers, to determine a forecasted slurry consumption value.

FIG. 7B illustrates use of the trained machine learning model to evaluate polishing liquid data 602, tool data 604, and wafer production data 606 to determine the polishing liquid supply parameters 610 associated with the systems 200, 300, according to some embodiments. In some embodiments, the trained machine learning model 720 evaluates one or more data of the polishing liquid data 602, tool data 604, and wafer production data 606 to determine a forecasted slurry consumption value and the polishing liquid supply parameters 610, which include a refill line and a mix-in volume for a tank (e.g., the supply tank 242).

A method 900 is illustrated in FIG. 9 in accordance with some embodiments. At 902, the method 900 includes determining a forecasted slurry consumption value. At 904, the method 900 includes determining a refill line associated with the forecasted slurry consumption value. At 906, the method 900 includes determining a mix-in volume associated with the forecasted slurry consumption value. At 908, the method 900 includes operating a supply tank containing polishing slurry, the operating being according to the refill line and the mix-in volume. The operating at 908 can include (i) determining whether liquid level of the polishing slurry is below the refill line by a continuous liquid level sensor assembly mounted on the supply tank, and (ii) in response to the liquid level of the polishing slurry being below the refill line, adding the mix-in volume of fresh polishing slurry to the supply tank.

A method 1000 is illustrated in FIG. 10 in accordance with some embodiments. At 1002, the method 1000 includes determining a liquid level of polishing slurry contained in a supply tank via a liquid level sensor assembly mounted to the supply tank, the liquid level sensor assembly extending continuously from a first end of the supply tank to a second end of the supply tank. At 1004, the method 1000 includes determining whether the liquid level is below a refill line. At 1006, the method 1000 includes, in response to the liquid level being below the refill line, forming mixed polishing slurry by adding a mix-in volume of fresh polishing slurry to the supply tank. At 1008, the method 1000 includes forming second polishing slurry by aging the mixed polishing slurry. At 1010, the method 1000 includes polishing a surface of a semiconductor wafer using the second polishing slurry by a polishing apparatus.

One or more embodiments involve a computer-readable medium comprising processor-executable instructions configured to implement one or more of the techniques presented herein. An exemplary computer-readable medium is illustrated in FIG. 11, wherein the embodiment 1100 comprises a computer-readable medium 1108 (e.g., a CD-R, DVD-R, flash drive, a platter of a hard disk drive, etc.), on which is encoded computer-readable data 1106. This computer-readable data 1106 in turn comprises a set of processor-executable computer instructions 1104 configured to implement one or more of the principles set forth herein when executed by a processor. In some embodiments 1100, the processor-executable computer instructions 1104 are configured to implement a method 1102, such as at least some of the aforementioned method(s) when executed by a processor. In some embodiments, the processor-executable computer instructions 1104 are configured to implement a system, such as at least some of the one or more aforementioned system(s) when executed by a processor. Many such computer-readable media may be devised by those of ordinary skill in the art that are configured to operate in accordance with the techniques presented herein.

In some embodiments, a method is provided. The method includes: determining a forecasted slurry consumption value; determining a refill line associated with the forecasted slurry consumption value; determining a mix-in volume associated with the forecasted slurry consumption value; and operating a supply tank containing polishing slurry, the operating being according to the refill line and the mix-in volume. The operating includes: determining whether liquid level of the polishing slurry is below the refill line by a continuous liquid level sensor assembly mounted on the supply tank; in response to the liquid level of the polishing slurry being below the refill line, adding the mix-in volume of fresh polishing slurry to the supply tank; and supplying the polishing slurry to a polishing apparatus that is operable to polish a surface of a semiconductor wafer.

In some embodiments, a method is provided. The method includes: determining a liquid level of polishing slurry contained in a supply tank via a liquid level sensor assembly mounted to the supply tank, the liquid level sensor assembly extending continuously from a first end of the supply tank to a second end of the supply tank; determining whether the liquid level is below a refill line; in response to the liquid level being below the refill line, forming mixed polishing slurry by adding a mix-in volume of fresh polishing slurry to the supply tank; forming second polishing slurry by aging the mixed polishing slurry; and polishing a surface of a semiconductor wafer using the second polishing slurry by a polishing apparatus.

In some embodiments, a system is provided. The system includes: a first tank operable to store base slurry; a second tank operable to generate polishing slurry including filtered base slurry generated from the base slurry; a third tank operable to supply the polishing slurry to a polishing apparatus; a liquid level sensor assembly mounted to the third tank, the liquid level sensor assembly extending continuously from a first end of the third tank to a second end of the third tank; and a controller in data communication with the liquid level sensor assembly. The controller is operable to: replace a first refill line associated with the liquid level sensor assembly with a second refill line that is at a different liquid level than the first refill line; determine whether a liquid level of the polishing slurry in the third tank is below the second refill line; and in response to the liquid level being below the second refill line, add fresh polishing slurry to the third tank.

Although the subject matter has been described in language specific to structural features or methodological acts, it is to be understood that the subject matter of the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least some of the claims.

Various operations of embodiments are provided herein. The order in which some or all of the operations are described should not be construed to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment provided herein. Also, it will be understood that not all operations are necessary in some embodiments.

It will be appreciated that layers, features, elements, etc. depicted herein are illustrated with particular dimensions relative to one another, such as structural dimensions or orientations, for example, for purposes of simplicity and ease of understanding and that actual dimensions of the same differ substantially from that illustrated herein, in some embodiments. Additionally, a variety of techniques exist for forming layers, regions, features, elements, etc. mentioned herein, such as at least one of etching techniques, planarization techniques, implanting techniques, doping techniques, spin-on techniques, sputtering techniques, growth techniques, or deposition techniques such as chemical vapor deposition (CVD), for example.

Moreover, “exemplary” and/or the like is used herein to mean serving as an example, instance, illustration, etc., and not necessarily as advantageous. As used in this application, “or” is intended to mean an inclusive “or” rather than an exclusive “or”. In addition, “a” and “an” as used in this application and the appended claims are generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Also, at least one of A and B and/or the like generally means A or B or both A and B. Furthermore, to the extent that “includes”, “having”, “has”, “with”, or variants thereof are used, such terms are intended to be inclusive in a manner similar to the term “comprising”. Also, unless specified otherwise, “first,” “second,” or the like are not intended to imply a temporal aspect, a spatial aspect, an ordering, etc. Rather, such terms are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B or two different or two identical elements or the same element.

Also, although the disclosure has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others of ordinary skill in the art based upon a reading and understanding of this specification and the annexed drawings. The disclosure comprises all such modifications and alterations and is limited only by the scope of the following claims. In particular regard to the various functions performed by the above described components (e.g., elements, resources, etc.), the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure. In addition, while a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.