CHEMICAL MECHANICAL PLANARIZATION (CMP) PADS WITH INTEGRATED WEAR INDICATOR

Description

BACKGROUND

Chemical mechanical planarization (CMP) is a crucial process in the semiconductor manufacturing industry. It involves smoothing and planarizing surfaces using a synergistic combination of chemical and mechanical forces. This process is essential for ensuring the flatness and uniformity of semiconductor wafers, which are critical for high-performance electronic devices. CMP utilizes a specially formulated slurry containing abrasive and corrosive chemicals along with a sophisticated polishing pad designed to distribute this slurry evenly across the wafer's surface. The goal is to remove excess material from the wafer and to level out any irregular topography, resulting in a perfectly flat or planar surface that is ideal for subsequent semiconductor processing steps.

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 is a schematic diagram of a chemical mechanical planarization (CMP) system, in accordance with some embodiments.

FIG. 2 is a diagram of a polishing pad that includes a plurality of wear indicators, in accordance with some embodiments.

FIG. 3A is an enlarged view of a wear indicator positioned within a groove of a polishing pad, wherein the polishing pad is new and the wear indicator has a height that is less than a height of the groove in which the wear indicator is positioned, in accordance with some embodiments.

FIG. 3B is an enlarged view of the wafer indicator positioned within the groove of the polishing pad of FIG. 3A, wherein the polishing pad has been used for a period of time and the wear indicator has the same height as the groove in which the wear indicator is positioned, in accordance with some embodiments.

FIG. 4 is an elevational view of a wear indicator in a groove of a polishing pad, wherein the wear indicator includes an opening or passage therethrough to allow flow of a slurry through the wear indicator, in accordance with some embodiments.

FIG. 5 is a perspective view of a wear indicator within the groove of a polishing pad, wherein the wear indicator comprises a plurality of wear indicators each having different heights to provide an indication of different levels of wear of the polishing pad, in accordance with some embodiments.

FIG. 6 is an elevational view of a wear indicator for a polishing pad that includes different colors or materials at different heights of the wear indicator, which allows a user or optical sensor to interpret different levels of wear of the polishing pad during operation, in accordance with some embodiments.

FIGS. 7A-7E depict various views of different wear indicators positioned in grooves of polishing pads, wherein each of the wear indicators depicted has a different shape, in accordance with some embodiments.

FIGS. 8A-8E depict top plan views of various patterns of wear indicator distributions across the top surface of polishing pads within grooves of the polishing pads, in accordance with some embodiments.

FIG. 9 is a flow diagram for a method of operating a CMP system to monitor the wear status of a polishing pad of the CMP system, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many 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 and/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 and/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 another 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 depicted 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 present disclosure provides a polishing pad for a chemical mechanical planarization (CMP) system that includes one more wear indicators that allow a user or a sensor system to easily determine a wear level of the polishing pad during operation. The present disclosure also provides a system including the polishing pad, a method for polishing a substrate using the polishing pad, and a method for monitoring the wear level of the polishing pad during use. In addition, elements, conditions or parameters illustrated in different embodiments can be combined or modified to form different combinations of embodiments as long as the elements, parameters or conditions used are not conflicted. For case of illustration, reference numerals with similar or same functions and properties are repeatedly used in different embodiments and figures.

FIG. 1 is a schematic diagram of a CMP system 10 according to some embodiments of the present disclosure. As shown in FIG. 1, the CMP system 10 includes a polishing head or carrier 100 and a platen 102. The polishing head 100 is configured to hold a substrate 101 targeted to a CMP operation. The platen 102 is configured to allow a polishing pad 104 to be disposed thereon. When the CMP system 10 is in use, the polishing pad 104 is disposed on the platen 102, and the substrate 101 is held by the polishing head 100 against the polishing pad 104. In some embodiments, the polishing pad 104 may include a single layer of material, and in other embodiments the polishing pad may include multiple layers of materials (e.g., one or more support layers bonded or otherwise affixed to a top layer of the polishing pad). In some embodiments, the substrate 101 is a wafer or a semiconductor substrate that has undergone one or more semiconductor processing steps. In some embodiments, the polishing head 100 is rotated along a central line 106 (indicated with a dashed line) of the polishing head 100, and thus the substrate 101 is also rotated against the polishing pad 104 during the CMP operation. In some embodiments, the central line 106 passes through a center of the substrate 101 so that the center of the substrate 101 is also a center of rotation of the substrate 101 in the CMP operation.

In some embodiments, the CMP system 10 includes a slurry delivery unit 108 and a control unit 110. The control unit 110 may include any combination of processors, memory, inputs, outputs, communication devices, etc. The slurry delivery unit 108 may be disposed over the platen 102, and supplies and deposits slurry 112 on the polishing pad 104 when the CMP operation is performed. The slurry 112 may be provided in a liquid or aqueous form via a nozzle of the slurry feed 108. A typical slurry 112 is a water-based solution and contains chemicals and physical abrasives which are used for polishing the substrate 101 in conjunction with the polishing pad 104. In some embodiments, the polishing abrasives in the slurry 112 may have different shapes, such as a ball shape, a spheroid shape, an ellipsoid shape, or the like. In some embodiments, the polishing abrasives in the slurry 112 are made of metal ceramic composites. In some embodiments, the polishing abrasives in the slurry 112 are made of corudum, tungsten carbide, silicon carbide (carborundum), titanium carbide, boron, boron nitride, rhenium diboride, stishovite, titanium diboride, diamond, carbonado, etc.

The cooperation between the slurry 112 and the polishing pad 104 removes material on the substrate 101 and tends to even out any irregular topography, making the substrate 101 flat or planar and suitable for subsequent processing steps. In some embodiments, the platen 102 is rotated along a central line 114 (indicated with a dashed line), and thus the polishing pad 104 is also rotated when the CMP system 10 is in use. The control unit 110 may be communicatively connected to the polishing head 100 and configured to send or receive one or more signals to or from the polishing head 100 in order to adjust a polish profile of the polishing head 100.

In some embodiments, the CMP system 10 also includes a pad dresser 116. The pad dresser 116 is disposed over the platen 102 and the polishing pad 104, and faces the polishing pad 104. During the CMP operation, the pad dresser 116 pushes on the polishing pad 104 with a downward force that brings the pad dresser 116 into contact with the polishing pad 104. As the polishing pad 104 is rotated by the platen 102 during the CMP operation, the pad dresser 116 roughens a polish surface or top surface S104 of the polishing pad 104 to provide mechanical mechanism of the polishing pad 104 on the substrate 101.

In some embodiments, the CMP system 10 may include one or more sensors 118 that are operative to detect a wear level of the polishing pad 104, so that the system may determine or predict when the polishing pad should be replaced or refurbished. The sensors 118 may be operatively coupled to the control unit 110 or to another computing system associated with the CMP system 10. The sensor 118 may achieve this sensing functionality by continuously or periodically monitoring one or more wear indicators (see FIG. 2) disposed on the polishing pad 104, which provide the sensor 118 with an indication of the wear level of the polishing pad over time. The sensor 118 may include one or more profile sensors, optical sensors (e.g., cameras), one or more laser sensors, other types of sensors, or combinations thereof. In some embodiments, in addition to or instead of a sensor system, an operator may be able to visually inspect the polishing pad 104 with their eyes and determine its wear level by viewing the one or more wear indicators of the polishing pad.

The sensors 118 may be strategically placed in relation to the polishing pad 104 they are configured to monitor. These sensors 118 may be positioned to effectively capture real-time data on the wear of the polishing pad's surface by capturing optical signals (e.g., images, video), by emitting and detecting a laser beam that reflects off the polishing pad 104, etc. This arrangement allows the sensors 118 to accurately determine the condition of the grooves of the polishing pad based on the wear indicators, ensuring that any significant wear or deformation that could impact the polishing process is promptly detected. In at least some implementations, the sensor data may be utilized to adjust CMP parameters dynamically. In at least some implementations, the sensors 118 feed data back to a computing system (e.g., processing unit 110), which then adjusts the polishing pad's rotational speed on the platen 102, the pressure applied by the carrier 100, the rate at which slurry 112 is dispensed from the system, or other system parameters. Further, as discussed below, once the wear indicator indicates that the polishing pad 104 should be replaced or refurbished, the system may initiate the required process to timely replace or refurbish the polishing pad 104 as needed, thereby minimizing downtime. Further, since the polishing pad 104 is not replaced until the wear indicator indicates that the polishing pad requires replacement, waste caused by prematurely replacing a polishing pad 104 is reduced, along with the additional downtime associated with replacing the polishing pad before replacement is needed.

FIG. 2 is an enlarged perspective view of a portion of a polishing pad 104a also shown in FIG. 1, depicting its polish or top surface S104a of a body 120a and a number of wear indicators 122a. As used herein, reference numerals appended with letters (e.g., a, b, c) may be similar or identical to the same reference numerals without letters or with different letters (e.g., 104, 104a, 104b). Accordingly, descriptions of components with the same reference numeral may have similar or identical properties as each other, where applicable. The polishing pad 104a may be made from one or more layers of a material (e.g., polyurethane), and may be directly mounted on the platen 102 (FIG. 1), which facilitates its rotation. The top surface S104a of the polishing pad 104a, which directly contacts the substrate 101 (e.g., wafer) during operation, may be important for its interaction with the abrasive slurry 112, which flows down from the slurry delivery unit 108 positioned above as shown in FIG. 1. The effective design of the polishing pad's surface S104a not only enhances the mechanical action on the wafer but also ensures that the chemical slurry is utilized efficiently throughout the planarization process.

The texture and porosity of the polishing pad 104a may be tailored to manage the slurry's 112 distribution as it is dispensed from the slurry delivery unit 108 above. This design ensures that the polishing pad 104a can hold an adequate amount of slurry 112 and distribute it evenly across the substrate's surface, which is important for achieving a uniformly polished surface. As shown in FIG. 2, the polishing pad 104a includes a plurality of arcuate-shaped grooves 124a that extend downward from the top surface S104a of the polishing pad. These grooves 124a may be optimized based on the specific characteristics of the substrates 101 being polished, ensuring that each polishing pad 104a meets the unique requirements of different semiconductor manufacturing processes. Also shown in FIG. 2 are the plurality of wear indicators 122a that are each positioned within one of the grooves 124a. As discussed in detail below, the wear indicators 122a may be observed by a sensor (e.g., sensor 118) or a human viewer to assess the wear level of the polishing pad 104a during use so that the polishing pad may be timely replaced or refurbished.

FIG. 2 shows a pattern of grooves 124a that are arcuately-shaped and extend radially outward from the center 126a of the polishing pad 104a. However, it should be appreciated that the embodiments of the present disclosure are not so limited. Various groove patterns may be implemented in the polishing pad's top surface S104a, and their relationship to slurry management may be tailored to specific applications or processing steps in the semiconductor manufacturing process. Groove patterns may include linear, radial, concentric grooves, arcuate patterns, or other patterns, wherein each pattern is designed to channel the slurry 112 effectively across the surface S104a of the polishing pad 104a to ensure consistent contact with the target substrate 101. The slurry 112, dispensed from the slurry dispense unit 108 directly above, uses these grooves 124a as pathways to reach all parts of the substrate 101 uniformly. This design advantageously prevents local over-polishing or under-polishing, which could lead to defects in the substrate 101. For example, linear grooves may direct the slurry 112 in a controlled manner, while radial and concentric patterns may help distribute the slurry outward from the center 126a of the polishing pad 104a. The geometry of these grooves 124a, directly carved into the polishing pad 104a that is mounted on the rotating platen 102, ensures that the slurry 112, fed from above, is used efficiently, enhancing the polishing process's effectiveness and consistency.

In some embodiments, the polishing pad 104a may be formed by three-dimensional (3D) printing. For example, the polishing pad 104a may be formed by selective laser sintering (SLS) of 3D printing. In some embodiments, a 3D printer may utilize polyurethane or another material to manufacture the polishing pad 104a. The method of selective laser sintering may form the grooves 124a in the top surface S104a and the wear indicators 122a in the grooves. Alternatively, the grooves 124a and/or the wear indicators 122 may be formed by machining the top surface S104a of the polishing pad 104a. “Machining” used herein means any of various processes in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process.

In some embodiments, the polishing pad 104a may be formed by maturing. The forming the polishing pad 104a may include the following steps, as a non-limiting example. A first layer of the polishing pad 104a may be formed. Thereafter, a first mask is disposed on the first layer of the polishing pad 104a. Afterwards, the first layer of the polishing pad 104a is matured after the disposing the first mask. Next, the first mask is moved from the first layer of the polishing pad 104a. Subsequently, wear indicators 122a are formed on the first layer of the polishing pad 104a within the grooves 124a using a similar process. The one or more layers may be made of material including polyurethane, but various embodiments of the present disclosure are not limited in this regard, other materials (e.g., rubber) may be also used to form the polishing pad 104a through maturing.

In some embodiments, the polishing pad 104a may be formed from any suitable polymeric material including, but not limited to, polyamide, polyimide, nylon polymer, polyurethane, polyester, polypropylene, polyethylene, polystyrene, polycarbonate, diene containing polymer, such as acrylonitrile ethylene styrene (AES), acrylic polymer, or a combination thereof. Embodiments of the present disclosure also contemplate the use of organic or inorganic materials that can be used as needed. The wear indicators 122a may be formed from the same material as the polishing pad 104a, or may be formed from different materials, including plastics, elastomers, metals, etc.

FIGS. 3A and 3B provide enlarged cross-sectional views of a polishing pad 104b, when the polishing pad is new (FIG. 3A) and when the polishing pad has been extensively used (FIG. 3B) and is due for replacement. Referring first to FIG. 3A, there is shown a wear indicator 122b positioned within one of the grooves 124b, the wear indicator including a top surface S104b having a height (H_wi) from a bottom surface 128b of the groove 124b that is lower than a height (H_g1) of the groove 124b in the body of the polishing pad 104b. As non-limiting examples, the height (H_wi) of the wear indicator 122b may be between 10% and 90% of the initial height (H_g1) of the groove 124b. Similarly, a width (W_wi) of the wear indicator 122b may be between 50% and 100% of the width (W_g) of the groove 124b. In the illustrated embodiment, the width (W_wi) of the wear indicator 122b is equal to or 100% of the width (W_g) of the groove 124b. As can be appreciated, the lower the height (H_wi) of the wear indicator 122b relative to the initial height of the groove 124b, the more wear may be inflicted on the polishing pad 104b before the groove 124b has substantially the same height as the wear indicator, wherein the user or sensor may observe the wear indicator and determine that the polishing pad should be replaced or refurbished. This is shown in FIG. 3B, wherein the height (H_wi) of the wear indicator 122b is substantially the same as the height (H_g2) of the worn-down groove 124b of the polishing pad 104. In this condition, observing the polishing pad 104b at a profile view will allow the user, profile sensor, optical sensor, or other detector to quickly determine that the polishing pad 104b is worn out because the wear indicator 122b will be visible in the groove 124b.

In at least some implementations, the one or more wear indicators 122b may be a different color from the top surface S104b, which may allow for better interpretation by an optical sensor or a user. As discussed further below, in at least some implementations the wear indicators 122b may include multiple colors which allow for determination of a degree or amount of wear of the polishing pad 104b.

FIG. 4 depicts a sectional view of a portion of the polishing pad 104c, including a wear indicator 122c disposed within a groove 124c of the polishing pad in the top surface S104c. In this embodiment, the wear indicator 122c includes an opening or passage 130 below a top surface 132 of the wear indicator which allows slurry 112 to flow therethrough. Thus, in this example, the wear indicator 122c does not substantially impede the flow of slurry 112, which allows for more uniform distribution of the slurry within the grooves 124c and top surface S104c of the polishing pad 104c. The size and shape of the opening 130 may be any suitable size and shape, so long as the wear indicator 122c maintains the top surface 132 which allows the viewer or sensor to determine when the top surface S104c that is adjacent the groove 124c has been worn down to the level of the top surface 132 of the wear indicator 122c. As non-limiting examples, the passage 130 may be circular, rectangular, or any other geometric shape and can extend to the bottom surface 128c of the groove 124c, effectively suspending the wear indicator 122c between the sidewalls of the groove, such that the opening 130 is defined on its top by a bottom surface 134 of the wear indicator, on its sides by the sidewalls of the groove 124c, and on its bottom by the bottom surface 128c of the groove.

FIG. 5 illustrates another embodiment of a wear indicator 122d for a polishing pad 104d. In this implementation, the wear indicator 122d may include a plurality of wear indicators 122d1, 122d2, 122d3, and 122d4 that each have a different height than the other wear indicators. In the illustrated embodiment, the first wear indicator 122d1 may have a height that is 1 mm below the top surface S104d of the polishing pad 104d, the second wear indicator 122d2 may have a height that is 2 mm below the top surface S104d of the polishing pad 104d, the third wear indicator 122d3 may have a height that is 3 mm below the top surface S104d of the polishing pad 104d, and the fourth wear indicator 122d4 may have a height that is 4 mm below the top surface S104d of the polishing pad 104d. It should be appreciated that these values are provided as examples for the purpose of illustration, and should not be considered to be limiting. By providing wear indicators with different heights, the user or sensor may be able to detect different levels of wear of the polishing pad 104d. For example, if the top surface S104d of the polishing pad 104d is at the same height as the second wear indicator 122d2, the user or sensor will know that the polishing pad is not so worn that it is at the height of the third wear indicator 122d3 or the fourth wear indicator 122d4. In at least some implementations, the different levels of wear may be used to determine or predict when the polishing pad 104d needs to be replaced, based on the timing of when the top surface S104d falls below each of the first, second, third, and fourth wear indicators 122d1-122d4.

In at least some implementations, the wear indicators 122d1-122d4 may be color coded to allow a user or sensor to quickly determine the level of wear of a polishing pad. For instance, the uppermost wear indicator 122d1 may be green, the next lower wear indicator 122d2 may be yellow, the next lower wear indicator 122d3 may be orange, and the lowest wear indicator 122d4 may be red. In such instances, the user or sensor may be able to observe the color that is visible and immediately know the level of wear (among four levels) of the polishing pad 104d. Providing indications of different levels of wear may allow for predicting when the polishing pad 104d will need to be replaced or refurbished in the future. In the illustrated embodiment, the overall depth (D_wi) of the four wear indicators 122d1-122d4 in the groove may be between 5 mm and 20 mm, as a non-limiting example. For instance, each of the wear indicators 122d1-122d4 may have a depth of 5 mm, so the total depth (D_wi) for all four wear indicators is 20 mm. As another example, each of the wear indicators 122d1-122d4 may have a depth of 1 mm, so the total depth for all four wear indicators is 4 mm. Each of the wear indicators 122d1-122d4 may have the same depth as the other wear indicators, or one or more of the wear indicators may have a different depth than the other of the wear indicators. Additionally, each of the wear indicators 122d1-122d4 may be the same shape and/or size as each other, or one or more of the wear indicators may have a different shape and/or size than one or more other wear indicators.

FIG. 6 is a sectional elevational view of a wear indicator 122e for a polishing pad 104e, according to one or more embodiments of the present disclosure. In this embodiment, the wear indicator 122e includes different colors or materials at different heights of the wear indicator, which allows a user or optical sensor to interpret different levels of wear of the polishing pad during operation. In the illustrated embodiment, a top portion 122e1 of the wear indicator 122e may have a height that is 1 mm below the surface S104e of the polishing pad 104e and may be colored with a first color (e.g., red), a second portion 122e2 of the wear indicator below the top portion may have a height that is 2 mm below the surface S104e of the polishing pad 104e and may be colored with a second color (e.g., light blue), a third portion 122e3 of the wear indicator below the second portion may have a height that is 3 mm below the surface S104e of the polishing pad 104e and may be colored with a third color (e.g., dark blue), and a fourth portion 122e4 of the wear indicator below the third portion may have a height that is 4 mm below the surface S104e of the polishing pad 104e and may be colored with a fourth color (e.g., green). Using this color coding, a user or a sensor may quickly determine a level of wear of the polishing pad 104e based on which color of the wear indicator 122e is currently visible. For instance, if the wear indicator 122e is dark blue (third portion 122e3), the user will know that the polishing pad 104e is more worn than if the wear indicator is red (first, top portion 122e1). It should be appreciated that these values are provided as examples for the purpose of illustration, and should not be considered to be limiting. By providing wear indicators with color coded portions having different heights, the user or sensor may be able to quickly detect different levels of wear of the polishing pad. In at least some implementations, instead of in addition to color-coding, the portions 122e1-122e4 may be coded using a different characteristic, such as differing materials that are detectable by a user or sensor, differing sizes, differing shapes, or other characteristics.

FIGS. 7A-7E depict views of different wear indicators 122f-122j positioned in a groove of polishing pads 104f-104j, respectively, wherein each of the wear indicators depicted has a different shape, in accordance with some embodiments. FIG. 7A depicts a polishing pad 104f having a box-shaped wear indicator 122f positioned within a groove of the polishing pad 104f. FIG. 7B depicts a polishing pad 104g having a triangle-shaped wear indicator 122g positioned within a groove of the polishing pad 104g. FIG. 7C depicts a polishing pad 104h having a cylinder shaped wear indicator 122h positioned within a groove of the polishing pad 104h. FIG. 7D depicts a polishing pad 104i having a cone-shaped wear indicator 122i positioned within a groove of the polishing pad 104i. FIG. 7E depicts a polishing pad 104j having a dome-shaped wear indicator 122j positioned within a groove of the polishing pad 104j. It should be appreciated that the illustrated shapes are provided as example shapes, and other shapes may be used in other embodiments. Further, in some embodiments that include multiple wear indicators, combinations of two or more shapes and/or sizes of wear indicators may be used.

FIGS. 8A-8E depict top plan views of various example patterns of wear indicators 122k-122o distributed across the top surfaces S104k-S104o of polishing pads 104k-104o, respectively, in accordance with some embodiments. In FIGS. 8A-8E, the grooves of the polishing pads 104k-104o are not shown to more clearly illustrate the various patterns of the wear indicators 122k-122o. In an actual polishing pad, each of the wear indicators 122k-122o would be in a groove of polishing pad.

FIG. 8A depicts a single wear indicator 122k positioned in a groove (not shown) on a top surface S104k of a polishing pad 104k. FIG. 8B depicts a polishing pad 104l that includes a plurality of wear indicators 122l arranged in a linear pattern on a top surface S104l that extends from a center of the polishing pad 104l to an outer edge of the polishing pad. FIG. 8C shows a polishing pad 104m that includes a plurality of wear indicators 122m arranged in a linear pattern than extends across an entire diameter of the top surface S104m of the polishing pad 104m. FIG. 8D depicts a polishing pad 104n wherein wear indicators 122n are arranged in a radial pattern within grooves on the top surface S104n of the polishing pad 104n. FIG. 8E depicts a polishing pad 104o wherein wear indicators 122o form a star-shaped pattern on the top surface S104o of the polishing pad 104o. It should be appreciated that various combinations of the example patterns provided may be used. Furthermore, the more or fewer wear indicators may be provided than illustrated in the Figures. Additionally, patterns other than those illustrated may be used. Generally, the more wear indicators that are present, and the more they are distributed across the area of the top surface S104 of the polishing pad 104, the better indication of wear may be obtained, especially for polishing pads that wear unevenly across different portions of the top surface of the polishing pad. Further, in at least some implementations, different shapes and sizes of wear indicators may be used together on the same polishing pad.

FIG. 9 is a flow diagram for a method 900 of operating a CMP apparatus and monitoring the wear status of a polishing pad of the CMP apparatus, in accordance with some embodiments. The method 900 may be performed using an of the various example components discussed herein. In at least some embodiments, the method 900 may include more or fewer acts than discussed in the illustrated embodiment. Additionally, in at least some embodiments, the acts of the method 900 may be performed in a different order than shown in FIG. 9.

The method 900 begins at 902, wherein a CMP apparatus is provided that includes a platen, a polishing pad mounted on the platen, a slurry feed system, and a carrier device. The polishing pad may be similar or identical to any of the polishing pads discussed herein. At 904, the method 900 includes operating the CMP apparatus over a time period. For example, the CMP apparatus may be operated over a number of hours, days, weeks, months, years, etc.

At 906, the method 900 includes monitoring a condition of the polishing pad over time using at least one observer by determining whether the height of the top surface of the polishing pad is substantially the same as the height of the top surface of the wear indicator. As discussed above, during use the top surface of the polishing pad wears down and eventually has a height that is substantially the same as the height of the top surface of the wear indicator. The observer may be a sensor system or a human, for example. At 908, responsive to determining that the height of the top surface of the polishing pad is substantially the same as the height of the top surface of the wear indicator, the method includes generating a signal that indicates that the polishing pad is worn and should be replaced. In at least some implementations, the signal may be an automated signal that is generated by a computing system after analyzing data from one more sensors. In at least some implementations, the signal may be generated by a human operator that has observed the wear indicator, either directly with their eyes or indirectly using one or more sensors. Once the signal is received, the polishing pad may be replaced or refurbished and a new polishing pad may be installed in the CMP apparatus.

According to one or more embodiments, a polishing pad is provided that includes a body configured to engage with a platen of a chemical mechanical planarization (CMP) apparatus. The pad also includes a plurality of grooves formed on a top surface of the body, the plurality of grooves sized and shaped to facilitate uniform distribution of a slurry across the top surface of the polishing pad during operation. The pad also includes a wear indicator positioned within one of the grooves, the wear indicator may include a top surface having a height that is lower than a height of the groove in the body of the polishing pad.

According to one or more embodiments, a chemical mechanical planarization (CMP) apparatus is provided that includes a platen. The apparatus also includes a polishing pad mounted on the platen to be rotated by the platen during operation. The polishing pad may include a body; a plurality of grooves formed on a top surface of the body, the plurality of grooves sized and shaped to facilitate uniform distribution of a slurry across the top surface of the polishing pad during operation; and a wear indicator positioned within one of the grooves, the wear indicator may include a top surface having a height that is lower than a height of the groove in the body of the polishing pad. The apparatus also includes a slurry feed system positioned above the polishing pad configured to dispense a slurry onto the surface of the polishing pad. The apparatus also includes a carrier device configured to hold and press a semiconductor wafer against the polishing pad. The apparatus also includes at least one sensor configured to detect a condition where, after use of the polishing pad, the height of the top surface of the body of the polishing pad is substantially the same as the height of the top surface of the wear indicator.

According to one or more embodiments, a method of operating a chemical mechanical planarization (CMP) apparatus is provided. The method includes providing a CMP apparatus that may include a platen, a polishing pad mounted on the platen, a slurry feed system, and a carrier device. The polishing pad may include: a body configured to engage with the platen; a plurality of grooves formed on a top surface of the body, the plurality of grooves sized and shaped to facilitate uniform distribution of a slurry from the slurry feed system across the top surface of the polishing pad during operation; and a wear indicator positioned within one of the grooves, the wear indicator may include a top surface having a height that is lower than a height of the groove in the body of the polishing pad. The method also includes operating the CMP apparatus over a time period. The method also includes monitoring a condition of the polishing pad over time using at least one human or machine-based observer by determining whether the height of the top surface of the polishing pad is substantially the same as the height of the top surface of the wear indicator. The method also includes responsive to determining that the height of the top surface of the polishing pad is substantially the same as the height of the top surface of the wear indicator, generating a signal that indicates that the polishing pad is worn and should be replaced.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.