MEMBRANE AND SUBSTRATE POLISHING DEVICE INCLUDING THE SAME

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2024-0121689, filed on September 6, 2024, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

1. Field of the Invention

One or more embodiments relate to a membrane and a substrate polishing device including the same.

2. Description of the Related Art

The manufacturing of semiconductor devices requires a chemical mechanical polishing (CMP) process, which includes polishing, buffing, and cleaning. Semiconductor devices are formed in a multilayer structure, with transistor elements having diffusion regions formed on a substrate layer. On the substrate layer, interconnecting metal lines are patterned and electrically connected to the transistor elements that form a functional device. As is well known, patterned conductive layers are insulated from other conductive layers by an insulating material, such as silicon dioxide. As more metal layers and associated insulating layers are formed, the need for flattening the insulating material increases. When flattening is not performed, the manufacturing of additional metal layers becomes substantially more difficult due to significant variations in surface topography. Furthermore, metal line patterns are formed of an insulating material so that a metal CMP process removes excess metal.

With technological advancements, the importance of substrate backside polishing is increasing. When polishing the backside of a substrate, since a membrane comes into direct contact with a pattern surface of the substrate, the pattern surface may be damaged by particles, defects, scratches, and/or static electricity. Therefore, a structure capable of minimizing damage to the pattern surface in the substrate backside polishing is required.

The above description has been possessed or acquired by the inventor(s) in the course of conceiving the present disclosure and is not necessarily an art publicly known before the present application is filed.

SUMMARY

Embodiments provide a membrane capable of minimizing a contact area between the membrane and a substrate.

Embodiments provide a membrane capable of transmitting pressure to a substrate through an internal pressure chamber while contacting only the outermost portion of the substrate.

According to an aspect, there is provided a substrate polishing device including a carrier head, a membrane connected to the carrier head, and a retainer ring connected to the carrier head to surround an outer side of the membrane. The membrane includes a side wall formed in an annular shape, a bottom flap extending in an inward direction from a lower end of the side wall and intended to come in direct contact with a substrate, and an upper flap extending from an upper end of the side wall and intended to connect to the carrier head.

In an embodiment, the bottom flap may extend from the lower end of the side wall toward a center of the membrane by a designated length so that a hollow is formed in a bottom surface of the membrane.

In an embodiment, based on a state in which the substrate is in contact with a lower surface of the bottom flap, a pressure chamber may be formed between a lower surface of the carrier head, the upper flap, the side wall, the bottom flap, and an upper surface of the substrate.

In an embodiment, the pressure chamber may be formed as a single chamber.

In an embodiment, the substrate polishing device may further include a first pressurizing unit configured to control an internal pressure of the pressure chamber in order to control a downward pressure applied to the substrate.

In an embodiment, the bottom flap may include a protrusion protruding upward from an inner end portion.

In an embodiment, the upper flap may include a first upper flap extending in an upward direction from the upper end of the side wall and a second upper flap extending in the inward direction from the upper end of the side wall.

In an embodiment, based on a state in which the first upper flap and the second upper flap are connected to the carrier head, an upper chamber is formed between the first upper flap, the second upper flap, and the carrier head.

In an embodiment, the substrate polishing device may further include a second pressurizing unit configured to control an internal pressure of the upper chamber in order to control a vertical position of the bottom flap or a degree of contact between the bottom flap and the substrate.

In an embodiment, a length by which the bottom flap extends in the inward direction from the lower end of the side wall may be less than a length by which the second upper flap extends in the inward direction from the upper end of the side wall.

In an embodiment, the first upper flap may include a bent portion formed bent to be vertically stretchable.

According to an aspect, there is provided a membrane to be connected to a carrier head, including a side wall formed in an annular shape, a bottom flap extending in an inward direction from a lower end of the side wall and intended to come in contact with a substrate, and an upper flap extending from an upper end of the side wall and intended to connect to a carrier head.

In an embodiment, the bottom flap may extend from the lower end of the side wall toward a center of the membrane by a designated length so that a hollow is formed in a bottom surface of the membrane.

In an embodiment, the bottom flap may include a protrusion protruding upward from an inner end portion.

In an embodiment, the upper flap may include a first upper flap extending in an upward direction from the upper end of the side wall and a second upper flap extending in the inward direction from the upper end of the side wall.

In an embodiment, a length by which the bottom flap extends in the inward direction from the lower end of the side wall may be less than a length by which the second upper flap extends in the inward direction from the upper end of the side wall.

In an embodiment, the first upper flap may include a bent portion formed bent to be vertically stretchable.

Additional aspects of embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure.

According to embodiments, damage to a pattern surface of a substrate during substrate backside polishing may be minimized by minimizing a contact area between a membrane and the substrate.

According to embodiments, pressure may be transmitted to a substrate through a pressure chamber formed between a membrane and the substrate while the membrane and the substrate only contact each other at the outermost portion of the substrate.

The effects of a membrane and a substrate polishing device including the same are not limited to the above-mentioned effects, and other unmentioned effects can be clearly understood from the following description by one of ordinary skill in the art to which the present disclosure pertains.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects, features, and advantages of the invention will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a perspective view schematically illustrating a substrate polishing device according to an embodiment;

FIG. 2 is a cross-sectional view schematically illustrating a substrate polishing device according to an embodiment;

FIG. 3 is a perspective view of a membrane according to an embodiment; and

FIGS. 4 and 5 are each a partial cross-sectional view of a substrate polishing device according to an embodiment, which is a cross-sectional view of a position corresponding to part B of FIG. 2.

DETAILED DESCRIPTION

Hereinafter, embodiments are described in detail with reference to the accompanying drawings. However, various modifications may be made to the embodiments, and the scope of the right should not be construed as limited to the embodiments set forth herein. The examples should be understood to include all changes, equivalents, and replacements within the idea and the technical scope of the disclosure.

The terminology used herein is for the purpose of describing particular examples only and is not intended to limit the embodiments. The singular forms "a," "an," and "the" used herein are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms "comprises/comprising" and/or "includes/including" when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

Unless otherwise defined, all terms including technical or scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which the embodiments belong. Terms, such as those defined in commonly used dictionaries, are to be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein.

When describing the embodiments with reference to the accompanying drawings, like reference numerals refer to like components and a repeated description related thereto is omitted. In the description of embodiments, detailed description of well-known related structures or functions is omitted when it is deemed that such description may cause ambiguous interpretation of the present disclosure.

In addition, in the description of the components of the embodiments, terms such as first, second, A, B, (a), (b), and the like may be used. These terms are used only for the purpose of distinguishing one component from another component, and the nature, the sequences, the orders, or the like of the components are not limited by the terms. It is to be understood that when a component is described as being "connected," "coupled," or "joined" to another component, the former may be directly "connected," "coupled," or "joined" to the latter or "connected," "coupled," or "joined" to the latter via another component.

The same name may be used to describe components having a common function in different embodiments. Unless otherwise mentioned, the description of one embodiment may be applicable to other embodiments. Thus, repeated description is omitted for conciseness.

FIG. 1 is a perspective view schematically illustrating a substrate polishing device according to an embodiment.

Referring to FIG. 1, a substrate polishing device 1 according to an embodiment may be a device for polishing a substrate. For example, the substrate polishing device 1 may be used in a chemical mechanical polishing (CMP) process of the substrate.

In an embodiment, the substrate may be a silicon wafer for manufacturing a semiconductor device. However, the type of substrate is not limited thereto. For example, the substrate may include glass for a flat panel display device (FPD) such as a liquid crystal display (LCD) or a plasma display panel (PDP).

In an embodiment, the substrate polishing device 1 may include a substrate carrier 10, a platen 20, a first pressurizing unit (e.g., a first pressurizing unit 31 of FIG. 2), and a second pressurizing unit (e.g., a second pressurizing unit 32 of FIG. 2).

In an embodiment, the substrate carrier 10 may grip the substrate. The substrate carrier 10 may grip the substrate by chucking the substrate and move the gripped substrate in an upward direction with respect to a polishing pad P. The substrate carrier 10 may perform polishing of the substrate by bringing the substrate, transferred in the upward direction with respect to the polishing pad P, into contact with the polishing pad P. The substrate carrier 10 may control a degree of polishing of the substrate by adjusting a friction force between the substrate and the polishing pad P by pressing the substrate in contact with the polishing pad P.

In an embodiment, the substrate carrier 10 may control a position of the substrate. The substrate carrier 10 may rotate around an axis perpendicular to a surface of the polishing pad P. The substrate gripped by the substrate carrier 10 may be polished while rotating in contact with the polishing pad P in accordance with the rotation of the substrate carrier 10.

In an embodiment, the substrate carrier 10 may move the substrate horizontally. The substrate may be transferred to a polishing position or removed from the polishing position in accordance with the horizontal movement of the substrate carrier 10.

In an embodiment, the substrate carrier 10 may move the substrate in an upward and downward direction relative to the ground. The substrate carrier 10 may move in an upward and downward direction relative to a substrate support portion for chucking/de-chucking of the substrate, or may move in an upward and downward direction relative to the polishing pad P for polishing of the substrate.

In an embodiment, the polishing pad P may be mounted on the platen 20. For example, the polishing pad P may be mounted on an upper portion of the platen 20. The platen 20 may polish a polishing surface of the substrate in contact with the polishing pad P while rotating around the axis.

FIG. 2 is a cross-sectional view schematically illustrating a substrate polishing device according to an embodiment. FIG. 3 is a perspective view of a membrane according to an embodiment. FIGS. 4 and 5 are each a partial cross-sectional view of a substrate polishing device according to an embodiment, which is a cross-sectional view of a position corresponding to part B of FIG. 2.

Referring to FIGS. 2 to 5, the substrate carrier 10 according to an embodiment may include a carrier head 11, a retainer ring 13, and a membrane 40.

In an embodiment, the carrier head 11 may form at least a portion of an exterior of the substrate carrier 10. Various components of the substrate carrier 10 may be connected to and/or disposed on the carrier head 11. The carrier head 11 may be configured to be rotatable around a central axis A.

In an embodiment, the retainer ring 13 may be connected to a lower portion of the carrier head 11 to surround the membrane 40 from an outer side of the membrane 40. The retainer ring 13 may surround a substrate W gripped by the membrane 40 from the outer side of the membrane 40. The retainer ring 13 may prevent the substrate W from being separated from a grip position. For example, the retainer ring 13 may support a side surface of the substrate W so that the substrate W may not be separated from the substrate carrier 10 due to vibration and/or friction generated during a polishing process.

In an embodiment, the membrane 40 may be connected to the lower portion of the carrier head 11. The membrane 40 may be a component to grip the substrate W. The membrane 40 may be formed of an elastically deformable material. For example, the membrane 40 may be used to grip the substrate W when polishing a backside of the substrate W. The backside of the substrate W may refer to an opposite surface of a pattern surface of the substrate W.

In an embodiment, the membrane 40 may include a side wall 41, a bottom flap 42, and an upper flap 43. The membrane 40 may be configured to be in contact with only a portion of the substrate W. For example, the membrane 40 may be formed in a ring shape with a hollow O in a center of the membrane 40 so that the membrane 40 may be in contact with only an outermost portion of the substrate W.

In an embodiment, the side wall 41 may be formed in an annular shape. The side wall 41 may be formed to have a substantially vertical direction. A support ring 50 may be coupled to an inner side and/or an outer side of the side wall 41. For example, an inner support ring 51 may be coupled to the inner side of the side wall 41. For example, an outer support ring 52 may be coupled to the outer side of the side wall 41. A groove may be formed in the side wall 41, to which the inner support ring 51 and/or the outer support ring 52 may be coupled.

In an embodiment, the bottom flap 42 may extend in a substantially inward direction from a lower end of the side wall 41. For example, the bottom flap 42 may extend in a substantially horizontal direction. The bottom flap 42 may be a portion to come in direct contact with the substrate W. The bottom flap 42 may extend from the lower end of the side wall 41 toward a center of the membrane 40 by a designated length so that a hollow may be formed in a bottom surface of the membrane 40. For example, a length by which the bottom flap 42 extends in the inward direction from the lower end of the side wall 41 may be less than a length by which a second upper flap 45 to be described below extends in the inward direction from an upper end of the side wall 41. The bottom flap 42 may be in contact with the outermost portion of the substrate W, as illustrated in FIG. 5. The bottom flap 42 may include a protrusion 421 protruding upward from an inner end portion of the bottom flap 42.

In an embodiment, the upper flap 43 may extend from the upper end of the side wall 41. The upper flap 43 may be a portion to be connected to the carrier head 11. The upper flap 43 may include a first upper flap 44 and a second upper flap 45.

In an embodiment, the first upper flap 44 may extend in a substantially upward direction (e.g., the vertical direction) from the upper end of the side wall 41. The second upper flap 45 may extend in a substantially inward direction (e.g., the horizontal direction) from the upper end of the side wall 41. The first upper flap 44 and the second upper flap 45 may include a protrusion 441 and a protrusion 451, respectively, formed protruding at an end portion thereof. The protrusions 441 and 451 of the first upper flap 44 and the second upper flap 45 may be coupled by fit to grooves formed in the carrier head 11 so that the membrane 40 may be connected to the carrier head 11.

In an embodiment, the first upper flap 44 may include a bent portion 442 formed bent to be stretchable in the vertical direction. The bent portion 442 may be formed by a partial section of the first upper flap 44 bent in the substantially horizontal direction. For example, the bent portion 442 may include a first bent portion 4421 and a second bent portion 4422. The first bent portion 4421 may be a portion of the first upper flap 44 bent in the inward direction from the side wall 41, and the second bent portion 4422 may be a portion of the first upper flap 44 bent in an outward direction from the first bent portion 4421. As a vertical distance between the first bent portion 4421 and the second bent portion 4422 increases or decreases, the first upper flap 44 may be stretched substantially in the vertical direction.

In an embodiment, based on a state in which the first upper flap 44 and the second upper flap 45 are connected to the carrier head 11, an upper chamber C2 may be formed between the first upper flap 44, the second upper flap 45, and the carrier head 11, as illustrated in FIGS. 4 and 5. The upper chamber C2 may refer to a space surrounded by the first upper flap 44, the second upper flap 45, and the carrier head 11. However, this is only an example, and the configuration surrounding the upper chamber C2 is not limited thereto. Other components may be added, or some of the above-described components may be omitted. The second pressurizing unit 32 may be configured to control an internal pressure of the upper chamber C2. As the second pressurizing unit 32 controls the internal pressure of the upper chamber C2, a vertical position of the bottom flap 42 and/or a degree of contact between the bottom flap 42 and the substrate W may be controlled. For example, when the internal pressure of the upper chamber C2 is in an initial state, the bottom flap 42 may be positioned spaced upwardly apart from the substrate W, as illustrated in FIG. 4. When the internal pressure of the upper chamber C2 increases, the first upper flap 44 and the second upper flap 45 may deform, and accordingly, the bottom flap 42 may substantially move downward, as illustrated in FIG. 5. Thus, by controlling the internal pressure of the upper chamber C2, the bottom flap 42 may be moved downward to contact the substrate W, and furthermore, the degree of contact between the bottom flap 42 and the substrate W may be controlled.

In an embodiment, based on a state in which the substrate W is in contact with a lower surface of the bottom flap 42, a pressure chamber C1 may be formed between a lower surface of the carrier head 11, the upper flap 43 (e.g., the second upper flap 45), the side wall 41, the bottom flap 42, and an upper surface of the substrate W. The pressure chamber C1 may refer to a space surrounded by the lower surface of the carrier head 11, the upper flap 43 (e.g., the second upper flap 45), the side wall 41, the bottom flap 42, and the upper surface of the substrate W. However, this is only an example, and the configuration surrounding the upper chamber C2 is not limited thereto. Other components may be added, or some of the above-described components may be omitted. The pressure chamber C2 may be a single chamber. When the degree of contact between the bottom flap 42 and the substrate W increases, a space between the bottom flap 42 and the substrate W may be sealed and the pressure chamber C1 may thus be a closed space substantially separated from an external space. The first pressurizing unit 31 may be configured to control an internal pressure of the pressure chamber C1. As the first pressurizing unit 31 controls the internal pressure of the pressure chamber C2, a downward pressure applied to the substrate W may be controlled. For example, in a state as illustrated in FIG. 5, by controlling the internal pressure of the pressure chamber C1, a pressure to press the substrate W downward against the polishing pad P may be controlled in a non-contact manner. Thus, by controlling the internal pressure of the pressure chamber C1, a degree to which the substrate W is pressed downward against the polishing pad P may be controlled in a non-contact manner, and a degree of polishing of the substrate W may thus be controlled. In addition, as the internal pressure of the pressure chamber C1 increases, a degree to which the bottom flap 42 presses the substrate W may increase, and a seal between the bottom flap 42 and the substrate W may be strengthened.

In this structure, a contact area between the membrane 40 and the substrate W may be minimized when polishing the backside of the substrate W, thereby minimizing damage to the pattern surface of the substrate W. In addition, by controlling the internal pressure of the pressure chamber C1 and/or the upper chamber C2, the degree to which the substrate W is pressed against the polishing pad P may be controlled, and accordingly, the degree of polishing of the substrate W may be controlled.

While the embodiments are described with reference to a limited number of drawings, it will be apparent to one of ordinary skill in the art that various alterations and modifications in form and details may be made in these embodiments without departing from the spirit and scope of the claims and their equivalents. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or substituted by other components or their equivalents.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.