TW200403788A - Carrier head with flexible membrane - Google Patents

Abstract

A carrier head for chemical mechanical polishing of a substrate has a flexible membrane extending beneath a base to define a chamber. The flexible membrane provides a substrate receiving surface, and can be configured so that a pressure profile applied to a substrate is substantially insensitive to retaining ring wear.

Description

200403788 发明. Description of the invention [Technical field to which the invention belongs] Chemical mechanical polishing support of thin films The present invention relates to a method including an elastic head and related methods. [Prior art] A typical integrated circuit uses a conductive layer,

Sequentially deposited and formed on the substrate, especially after the silicon layer or the insulating layer is eaten, and then proceeded to ... Generate electricity: Erzhi, when each layer of the layer is sequentially deposited and etched, the exposed surface of the substrate is then ... The layer 1 + surface gradually becomes uneven. This uneven surface will produce 4 problems in the photolithography step of the integrated electric meter, so it is necessary to periodically flatten the substrate. An accepted planarization chemical mechanical polishing (CMP) method. This planarization method usually requires the substrate to be cracked on a carrier or abrasive, and the exposed surface of the substrate faces a movable abrasive. The surface, such as rubbing some pieces, the abrasive pad can have a durable and rough surface.

The "quasi" grinding pad or a grinding pad containing abrasive particles, a fixed abrasive, and a grinding pad, the carrier head applies a controlled load of the substrate and pushes it towards the grinding pad, which contains at least one chemically active ingredient Pohshin slurry 'and when standard abrasive pads are used, abrasive particles are supplied to the surface of the abrasive pads. Some carriers include an elastic film with a mount that receives the substrate On the surface, the chamber behind the elastic film is compressed to cause the film to expand outwards, so that a load is applied to the substrate. Many carrier heads 3 200403788 include a retaining ring around the substrate at the same time, for example, to fix the load. The substrate in the head is below the elastic film. [Summary of the Invention] In a certain aspect, the present invention is directed to a carrier head for chemical mechanical polishing of a substrate. The carrier head includes a base and an elastic film. An elastic film extends below the base to form a compartment and provides a substrate-receiving surface. Usually for a certain state ' The invention features a carrier head for chemical mechanical polishing of a substrate. The carrier head includes a base, a retaining ring surrounding the substrate on the receiving surface of the substrate, and an elastic film which is formed below the base. A compartment provides the substrate receiving surface, and the elastic film can be configured so that the pressure profile applied to the substrate can be substantially unaffected by the wear of the retainer. Special embodiments may include one or more of the following features, The elastic film may include a central portion having a substrate receiving surface, and a curved portion having a first end. The first end is combined with the base portion so that a payload area can follow the curved portion. The distance between the first end point and the center portion is reduced and reduced. Generally, in another aspect, the invention is characterized by a carrier head for chemical mechanical polishing of a substrate, the carrier head comprising a base portion and a Elastic film 'The elastic film extends below the base to form a compartment and provides the substrate receiving surface. The elastic film can It includes a central portion with a substrate receiving surface 'and a curved portion with a first end point. The first end point is connected to the base portion. A particular embodiment of the present invention may include one or more of the following features, the curved portion The base portion can be directly or indirectly connected to the base portion. The combination of the first end point and the base portion allows the payload area to decrease as the distance between the first end point of the curved portion and the center portion decreases. The elastic film can also be A peripheral portion including the edge of the central portion is less subject to deformation than the central portion, and the peripheral portion may also be connected with an internal film holding and / or supporting element. The elastic film may further Including an extension (extension), the extension connecting the peripheral portion and the second end of the curved portion, the first end of the curved portion may be radially inside the second end of the curved portion, At the same time, the extension can be pulled in. The carrier head may include a retaining ring surrounding the substrate on the receiving surface of the substrate. The extension can be moved so that the pressure profile applied to the substrate can be substantially not affected by the wearing of the retaining ring. The extension can also be rotated and As a result, the area of the payload applied to the peripheral portion is reduced, and at the same time, the increased load on the edge of the film caused by at least a part of the abrasion of the retainer can be offset. The carrier head may include two curved portions, each of which has a first end point connected to the base portion, and the elastic film may also include a peripheral portion connected to an internal film clamp, which is adjacent to the two curved portions. The lower one, and allows the lower one of the two f-curved parts to move freely. The two curved parts can also define two chamber pressures in the bearing head. Generally speaking, in another aspect, the It is characterized in that it is an elastic film used with a carrier head of a chemical mechanical polishing device 5 200403788. The elastic film may include a central portion having a receiving surface of the substrate, and a curved portion having a first end point. The first end The point is connected to the base of the load head, and the curved portion is planned so that the pressure profile of the central portion applied to the substrate can be substantially unaffected by the vertical movement of the vertical position of the central portion relative to the first end of the curved portion. . A special embodiment of the present invention may include one or more of the following features. The elastic film may also include a peripheral portion that connects the second end of the curved portion to the central portion. The peripheral portion is more than the central portion. It is not subject to deformation, and at the same time, the peripheral part can be connected with an internal membrane inflammation. The elastic film may also include an extension portion that connects the peripheral portion to the first end of the curved portion. The extension portion can be rotated when pulled by the curved portion. The curved portion may include two curved portions. The elastic film may also include a peripheral portion, the peripheral portion is connected to an internal film holder, and at the same time, the second end of each curved portion is connected to the central portion, and the internal film holder is adjacent to the lower portion of the two curved portions. And allow the lower one of the two wild songs to move freely. Generally speaking, in another aspect, the present invention is characterized by a method for grinding a substrate, the method comprising mounting a substrate on a carrier head of a chemical mechanical polishing device such that a first side of the substrate abuts the carrier head, The carrier head includes a base portion, a retainer, and an elastic film. The elastic film includes a center portion to provide a mounting surface of the substrate, and the substrate is polished using a polishing pad, wherein the polishing pad and the base One of the first sides of the substrate is in contact, and the second side of the substrate is in contact with the first side of the substrate. During grinding, the elastic film can be moved so that the profile of the pressure applied to the substrate can be substantially not affected by the wear of the retainer.

Generally speaking, in another aspect, the present invention is characterized by an operation method of an elastic film bending portion, which connects a load head and a peripheral portion of the elastic film. The method includes maintaining a position of an arm bending portion so that It is substantially parallel to the substrate installed at the center of the elastic film, while the retaining ring of the bearing head maintains the original size. The first end of the curved portion is connected to the bearing head, and an extension is rotated when grinding is performed. To the retainer, the extension connects the second end of the curved portion and the peripheral portion of the elastic film, and when the retainer wears, rotates the extension toward the curved portion.

The present invention can implement one or more of the following advantages. An elastic film can be planned so that the bearing head of the chemical mechanical polishing device is less affected by the wear of the retainer. An elastic film can include a bend, and the bend can extend through an extension. When the retaining ring is worn, the extension portion is pulled by the bending portion to rotate, causing the effective load area on the peripheral portion to decrease as the extension portion is pulled. It is planned so that the payload area decreases as the distance between the first end point of the curved portion and the center portion of the elastic film decreases. [Embodiment] As described above, some of the carrier heads include an elastic film and a retainer, and the elastic film has a mounting surface for receiving the substrate, and the retainer is used to fix the substrate in the carrier head to the elasticity. Under the film, a chamber behind the elastic film is pressed to cause the film to expand outward, thus applying a negative 7

Kil ^ 00403788 is carried on this substrate. Unfortunately, in some film designs, the pressure distribution of the film will follow the wear and tear? The text change, which is the point of contact between the film and the rest of the carrier head when the retainer is worn. (Attachment point)

Will move closer to the polishing pad, and the lowered contact point will press down the outer edge portion of the film, so an extra load will be generated on the edge of the film, and as the ring wears, the periphery of the substrate will be polished Reduced rate If the polishing rate changes with the wear of the guard ring, the polishing profile will not be consistent between different wafers, so it will be very useful to have a carrier head that is not affected by the wear of the guard ring. Referring to FIG. 1, one or more substrates 10 will be ground by a chemical mechanical polishing (CMP) device including a carrier head 100. A description of a suitable CMP device can be referred to the figure of US Patent No. 5,73 8,574 And description, the completeness of this patent is incorporated herein by reference. The carrier head 100 includes a base assembly 104,

A retainer 1 10 and an elastic film 108, which is connected to the base 104 and stretched under it to form a pressurizable chamber 106. Although not shown in the figure, the load bearing The head may still contain other components, such as a housing for movable suspension of the base 104, a gimbal mechanism for rotation of the base 104 (considered as part of the base assembly), the base A loading chamber between 04 and the housing, one or more supporting structures in the pressurizable chamber 106, or contacting the inner surface of the elastic film 1 or several inner thin films 8 200403788 The film is used to yoke on the The substrate is supplemented with pressure. For example, the carrier head 100 can be, for example, U.S. Patent No. 6,183,354, or U.S. Patent Application No. 09 / 47,080 (filed on December 23, 999), or U.S. Patent Constructed as described in application number 09 / 712,389 (filed on 13/13/2000), the complete disclosure of which is incorporated herein by reference. Referring to Figures 2A and 2B, the elastic film 108 is made of an elastic material, such as neoprene, chloroprene, ethylene propylene rubber, or silicone, such as The elastic diaphragm 108 can be made of compression molded or liquid injection molded stone ketone. Compared with the compression molding process, the liquid injection molding process produces a softer material. As will be described later, the turning ability of the bent portion of the elastic film 108 can be increased. The elastic film 108 should be non-sticking, durable and stable to the grinding process. The elastic film 108 can include a central portion 120 having a substrate mounting surface 122, and one extending from the polishing surface. The unfolded peripheral portion 124, an elastic extension portion 126, and an inwardly extending bending portion 128, wherein the bending portion 128 has an inner edge that grips the base portion 104. The central portion 120 of the elastic film 108 may include a fiexibie Ηρ portion as discussed in US Patent No. 6,210,255, the complete disclosure of which is incorporated herein by reference. The peripheral portion 124 is relatively unaffected by deformation relative to other portions of the elastic film 108. For example, as shown in FIGS. 2A and 2B, the peripheral portion ι24 may be thicker than the central portion 120 or the f-curved portion 28. Alternatively, the peripheral portion 9 200403788 1 24 may be made of a harder material than other portions of the elastic film 108, or the peripheral portion 124 may include a reinforcing material or may surround a support or spacer structure (see (Figure 3 Α) Stretch to avoid distortion. The extension portion 126 has a base portion 130 connected to the peripheral portion 124, and has an end point 1 2 2 connected to the curved portion 1 2 8 while the extension portion 1 2 6 can be planned so that the end point 1 2 2 can be In response to the pull from the curved portion 1 2 8, it rotates inward. As shown in Figures 2A and 2B, when the retainer 11 is worn, the contact point (attachment point) of the curved portion 128 and the base portion 104 will move closer to the abrasive pad. When the clamped end of the curved portion 128 moves downward, the f-curved portion 128 will pull the extension portion 126 downward, thereby reducing the payload area, that is, covering the load area portion of the peripheral portion 124, and so on. The proportion reduces the load on the edge of the thin chess piece. This reduction in load can compensate for the increased load after wear of the retainer. Therefore, the application of the carrier head can provide a more uniform polishing pressure profile between different wafers. As a result, the polishing process, especially the polishing rate profile, is more stable and More repeatable, and because the process is less sensitive to the wear of the retainer, or is substantially unaffected by the wear of the retainer, the retainer can withstand greater wear and tear and can therefore be used for longer periods of time Or repair. Of course, when the retainer wears to a certain-considerable extent, the pressure profile will become sensitive to the wear of the retainer. As shown in Figures 3A-3C, in another embodiment, the f-curves 128 and 328 are connected to the base 104, and the use of two bends will generate two pressure chambers 344, 346. This configuration is available In U.S. Patent Application No. 10 200403788 09/7 12,389 (the complete part of the patent is the central part of the curved part 1 2 8 support element 342 the inner film is made of hard metal or hard-recorded steel. Such as extension 3B The part 1 2 6 turns. The increase of the effective pressure peripheral part 124 leads to the increase of the base. The extension 328 pulls outward like the 3C membrane 1 08. When the upper part of the curved part is lowered, the lower part of the effective force compartment 344 is reduced , It will increase the wear caused by the sharp corners of the effective film clamping caused by the bearing heads described in each other (filed on March 13th, 2000). Included in this article. As shown in Figure 3A, the initial configuration of 328 and 328, which are approximately parallel to the elastic film-shaped inner film holder 340, and a ring-shaped peripheral portion 124 together strengthen the elastic film. &Quot; 〇〇 and the support element 342 are made of steel hard material, 2 materials, such as the inner thin When the pressure in the pressure chambers 344 and 346 of the clamping 340 is not increased, it starts to turn outwards. With this extension, 1 2 6 gradually rotates outward the area of the force, that is, xi · # ^ ^ A pressure chamber 344 applied to the horizontal area is also identified. _ 嶒 Plus' The edge of the material of this effective pressure area is under the first M AAw η Α Λ Λ-the load extension 12 6 under the pressure chamber 344 And the taxi /-^ 丄 卜% turn at the same time lead the two curved parts 1 2 8 as shown in the picture, when the retainer! 〖Η & When the virtual space 丨 10 wears down, the elasticity is thinner than the base 104 and moves towards Bu Mingming > the outer wall ^ π, the first pressure gall 344 1 2 8 extends the extension μ 1, & W 126 is pulled in, so it helps the pressure area and the edge load, but the bent portion 328 is lowered to contact the inside and when the first pressing film is clamped 340

The edge load and the two curved portions 128 and 328 should be balanced with each other. Carefully choose a thin film material or the taper angle. These effects can be balanced in the retainer, and the edge load can be reduced or minimized. . 11 200403788 However, the result of the balance of the two effects may not be consistent, so that the final

There are many changes in the edge load. If we only focus on the moving effect of the curved portion 128 above the first pressure chamber 344, it will help improve the consistency. As shown in Figure 4, the movement of the curved portion 328 below the first pressure chamber 344 The edge load effect caused can be reduced by reducing the contact surface between the curved portion 328 and the inner film holder 440, so in order to eliminate or greatly reduce the clamped portion 328 below the first pressure chamber 344 and the inner film holder The contact of the upper surface of 440 must reduce the inner film clamping 44. The elimination or reduction of the contact between the curved portion 328 and the upper surface of the inner film 440 can reduce the sensitivity of the retainer wear, because when the retainer u When worn, the curved portion 328 can still move freely up and down, so that it does not affect the edge load of the substrate. Although the foregoing has directly described several embodiments of the present invention, other modifications or further embodiments can also be designed in accordance with the spirit of the present invention without departing from the scope defined by the present invention. For example, the diagnostic film can be fixed at different positions on the carrier head, such as being clamped in the retainer ^ The inward extension of the base can be floated or opened into several structures, and what should be understood is sensitivity, which may not have this other reality. The thin film rests on the film, and the support knot can fix the film even if the film contacts the embodiment. For example, the special design of the thin structure and the fixed film is still ground. The pad is covered by a support structure, and the support is not a single Piece of film, the curved part of the film can be fixed to a peripheral part supported by the film, and the special shape really reduces the wear of the retainer, such as the bearing head or the retaining head does not have a retainer at all The scope of the definition of the scope of patent application f- S '-^ ^ 12 200403788 [Brief description of the drawings] Details of one or more embodiments of the present invention, as well as other features, advantages and purposes, can be changed after referring to the following drawings Thorough understanding. Figure 1 is a cross-sectional view of a bearing head containing an elastic film; Figure 2A is a partial expanded view of the bearing head of Figure 1; Figure 2B is a schematic diagram of the elastic film after the retainer is worn; Figures 3A-3C are Schematic diagram of the elastic film operation of each bend

FIG. 4 is a schematic diagram of an elastic film having two curved portions and a cut back clamp; the same reference symbols in different drawings represent the same components. [Simple description of component representative symbols]

10 Base material 100 Carrier head 104 Base 106 Pressurizable chamber 108 Elastic film 110 Retainer 120 Central portion 122 Substrate mounting surface 124 Peripheral portion 126 Extension 13 200403788 128 Bend 130 Base 132 End point 328 Bend 340 Inner film clamp Holding 342 support element 344 pressure chamber 346 pressure chamber 440 film clamping

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Claims (1)

200403788 Patent application park: 1. A carrier head for chemical mechanical polishing of a substrate, the carrier head includes at least: a base; A retainer surrounds the substrate on a substrate receiving surface; and an elastic film extends below the base to form a compartment, the elastic film provides the substrate receiving surface, and can be planned so that the The pressure profile can be largely unaffected by the wear of the retainer. 2. The bearing head according to item 1 of the scope of patent application, wherein the elastic film further comprises a central portion having a substrate receiving surface and a curved portion having a first end point, the first end point being combined with the base portion The payload area is reduced as the distance between the first end of the curved portion and the central portion is reduced. 3. A carrier head for chemical mechanical polishing of a substrate, the carrier head comprising at least: a base; and an elastic film extending below the base to form a compartment and providing a substrate receiving surface, the elastic film further includes A central portion having a substrate receiving surface and a curved portion having a first end point, the first end point is connected to the base portion. 15 200403788 4. The bearing head according to item 3 of the scope of patent application, wherein the bent portion is directly connected to the base portion. 5. The bearing head according to item 3 of the scope of patent application, wherein the bent portion is indirectly connected to the base portion. 6. The bearing head according to item 3 of the scope of patent application, wherein the elastic film can be planned so that the payload area decreases as the distance between the first end point of the curved portion and the center portion decreases. 7. The bearing head according to item 3 of the scope of patent application, wherein the elastic film includes a peripheral portion at an edge of the central portion. 8. The bearing head according to item 7 of the scope of patent application, wherein the peripheral portion is less subject to deformation than the central portion. 9. The carrier head according to item 7 of the scope of patent application, wherein the peripheral portion is connected with an internal film clamp. 10. The bearing head according to item 9 of the patent application scope, wherein the peripheral portion is connected with a supporting element. 1 1 The bearing head according to item 7 in the scope of patent application, wherein the elastic film includes an extension portion connecting the peripheral portion and a second end point of the curved 16 200403788 portion. 1 2. The bearing head according to item 11 of the scope of patent application, wherein the extension portion rotates when being pulled by the bending portion. 1 3 The bearing head according to item 11 of the scope of patent application, wherein the extension portion is rotated so that a payload area applied to the peripheral portion is reduced as the extension portion is pulled. 14. The bearing head according to item 11 of the scope of patent application, wherein the first end of the curved portion is radially inside the second end of the curved portion, and at the same time, the extension portion can be pulled inward. 15 The carrier head according to item 11 of the scope of patent application, the carrier head further comprising at least one retaining ring surrounding the substrate on the receiving surface of the substrate. 16 The bearing head according to item 15 of the scope of patent application, wherein the extension is moved so that the pressure profile applied to the substrate is substantially unaffected by the wear of the retainer. 17. The carrier head according to item 15 of the scope of patent application, wherein the extension portion is rotated to reduce the effective load area applied to the peripheral portion, and at the same time, at least a portion of the guard ring is worn to increase the edge of the film. 17 200403788 The load was blocked. 1 8. The carrier head according to item 3 of the scope of patent application, wherein the elastic film includes two curved portions, each of which has a first end point connected to the base portion. 19 · The carrier head according to item 18 of the scope of patent application, wherein the elastic film includes a peripheral portion, the peripheral portion is connected to an internal film holder, and the internal film holder is adjacent to the lower one of the two curved portions. And allows the lower of the two bends to move freely. 20. The bearing head according to item 3 of the patent application scope, wherein the bent portion defines two pressure chambers in the bearing head. 2 1 · — An elastic film of a carrier head used in combination with a substrate chemical mechanical polishing device, the elastic film includes at least: A central portion having a substrate receiving surface; and a curved portion having a first end point, the first end point being connected to a base portion of the carrier head, wherein the curved portion is planned so that the central portion is applied to the substrate The pressure profile can be substantially unaffected by the vertical movement of the vertical position of the central part relative to the first endpoint of the curved part. 22 · The elastic film according to item 21 of the scope of patent application, the elastic film further comprises at least: 18 200403788 a peripheral portion, which connects a second end point of the curved portion and the central portion. 23. The elastic film according to item 22 of the scope of patent application, wherein the peripheral portion is less subject to deformation than the central portion. 24. The elastic film according to item 22 of the scope of patent application, wherein the peripheral portion is connected with an internal film clamp. 25. The elastic film according to item 22 of the scope of patent application, the elastic film further comprising at least: an extension portion connecting the peripheral portion and the second end point of the curved portion. 26. The elastic film according to item 25 of the scope of patent application, wherein the extending portion is rotated when being pulled by the bending portion. 27. The elastic film of claim 21, wherein the elastic film includes two bent portions. 28. The elastic film according to item 27 of the scope of patent application, the elastic film further comprising at least a peripheral portion, the peripheral portion being connected to an internal film to clamp and connect the central portion and the second end point of each curved portion, The inner film is clamped next to the lower one of the two bends, and the lower one of the two bends is allowed to move freely as in 19 200403788. 29. A method for grinding a substrate, the method at least comprising: mounting a substrate on a carrier head of a chemical mechanical polishing device, so that a first side of the substrate abuts the carrier head, the carrier head includes a base, a A retainer and an elastic film including a central portion to provide a mounting surface of the substrate; and A polishing pad is used to grind the substrate, wherein the polishing pad is in contact with a second surface of the substrate, and the second surface of the substrate is opposite to the first surface of the substrate; wherein, during grinding, The elastic film can be moved so that the pressure profile applied to the substrate can be substantially not affected by the wear of the retainer. 3 0. A method of operating a curved portion of an elastic film, the curved portion is connected to a bearing head and a peripheral portion of the elastic film, the method includes at least: Maintain the position of a bend so that it is approximately parallel to the substrate installed at the center of the elastic film, while the retaining ring of the load head maintains the original size, and the first end of the bend is connected to the load head; when grinding When in progress, rotate an extension toward the retainer, the extension connecting the second end of the bend and the peripheral portion of the elastic film; and when the retainer wears, rotate the extension toward the bend . 20