Wafer polishing head and chemical mechanical polishing apparatus

Abstract

The utility model provides a kind of wafer grinding head and chemical mechanical grinding equipment, wherein wafer grinding head includes grinding head main part, bottom is divided into N grinding pressure area and N grinding gap area, each described grinding pressure area is provided with pressure diaphragm, the bottom of each described grinding gap area is provided with gap diaphragm, and the pressure diaphragm and the gap diaphragm are respectively independently controlled pressure, the pressure diaphragm and the gap diaphragm are used to exert pressure on wafer;Fixed ring, be located at the bottom edge of described grinding head main part, for fixing the wafer.The wafer grinding head provided by the utility model is provided with pressure diaphragm in N grinding pressure area, and gap diaphragm is provided at the bottom of grinding gap area, independently controlled pressure diaphragm and gap diaphragm internal pressure is used, to ensure that the pressure exerted on wafer surface by grinding head is uniform and continuous, so as to improve the effect of wafer surface grinding planarization processing.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor processing equipment technology, and in particular to a wafer grinding head and a chemical mechanical polishing device. Background Technology

[0002] Chemical mechanical polishing (CMP) equipment is an important piece of equipment in the semiconductor wafer manufacturing process. It combines chemical etching and mechanical grinding to achieve global surface planarization.

[0003] CMP equipment has a grinding head, which is typically divided into multiple zones. The air pressure in each zone is independently controlled to adjust the pressure applied to different locations on the wafer, ensuring uniform wafer grinding. However, in actual operation, there is an interface between adjacent zones, where the pressure is lower than in adjacent zones. This results in uneven and discontinuous pressure applied to the wafer surface. During grinding, this uneven pressure leads to different grinding rates in different zones, resulting in varying thicknesses and hindering overall wafer planarization. Utility Model Content

[0004] The purpose of this invention is to provide a wafer grinding head and a chemical mechanical polishing device to improve the effect of wafer surface planarization.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a wafer polishing head, comprising a polishing head body, the bottom of which is divided into N polishing pressure regions and N polishing gap regions, each of the polishing pressure regions being provided with a pressure film, and each of the polishing gap regions being provided with a gap film at its bottom, wherein the pressure film and the gap film are independently controlled, and both the pressure film and the gap film are used to apply pressure to the wafer; A retaining ring is located at the bottom edge of the grinding head body and is used to fix the wafer. In some embodiments, all N pressure films are concentric with the grinding head body, and the diameter of the N pressure films gradually increases from the center to the edge of the grinding head body; One of the grinding gap regions is located between the outermost grinding pressure region and the fixing ring, and the remaining N-1 grinding gap regions are located between two adjacent grinding pressure regions.

[0006] In some embodiments, each of the pressure diaphragms is provided with an air supply hole, which is connected to an external pressure control device via a pipeline.

[0007] In some embodiments, the wafer grinding head further includes N partition rings, each partition ring having an air supply channel, and each air supply channel communicating with the corresponding gap film; One of the partition rings is located between the outermost pressure film and the fixing ring, and is used to connect the outermost pressure film and the fixing ring. The remaining N-1 partition rings are respectively disposed in the corresponding grinding gap regions to connect two adjacent pressure films.

[0008] In some embodiments, the gap film is an annular sheet structure; The outer edge of the outermost gap membrane is sealed to the inner wall of the fixing ring, and the inner edge is sealed to the bottom of the outermost pressure membrane. The gap membrane located between two adjacent pressure membranes has its outer side sealed to the bottom of one of the adjacent pressure membranes and its inner side sealed to the bottom of the other adjacent pressure membrane.

[0009] In some embodiments, the pressure diaphragm is a hollow diaphragm, and the air supply hole is located at the top of the hollow diaphragm.

[0010] In some embodiments, the grinding head body has a pressure chamber at the top; The pressure chamber is provided with a first delivery pipe and a second delivery pipe. The first delivery pipe is connected to the air supply hole, and the second delivery pipe is connected to the gap membrane. Both the first delivery pipe and the second delivery pipe are connected to an external pressure control device through pipelines.

[0011] In some embodiments, the bottom of the grinding head body is a groove structure, and both the pressure film and the gap film are disposed within the groove structure.

[0012] In some embodiments, the value of N ranges from 3 to 8.

[0013] In a second aspect, embodiments of the present invention provide a chemical mechanical polishing apparatus, including a polishing platform, a polishing pad, and the aforementioned polishing head; The grinding pad is disposed on the grinding platform; The grinding head is positioned corresponding to the grinding pad and is used to press the wafer against the grinding pad. The beneficial effects of the wafer grinding head and chemical mechanical polishing equipment provided by this utility model are as follows: This application divides the bottom of the grinding head body into N grinding pressure areas and N grinding gap areas, and sets pressure films in the N grinding pressure areas and gap films at the bottom of the grinding gap areas. By independently controlling the pressure of the pressure films and the internal pressure of the gap films, the pressure applied by the grinding head to the wafer surface is ensured to be uniform and continuous, thereby improving the effect of wafer surface grinding and planarization. Attached Figure Description

[0014] Figure 1 A cross-sectional view along the axial direction of the wafer grinding head provided in the embodiment of this utility model; Figure 2 A top view of the wafer grinding head provided in the embodiment of this utility model; Figure 3 A schematic diagram of the structure of the chemical mechanical grinding equipment provided in the embodiments of this utility model.

[0015] Figure label: Grinding head body 1, pressure diaphragm 11, air supply port 111, gap diaphragm 12, partition ring 13, pressure chamber 14. 2. Fixing ring, 100. Grinding head, 200. Grinding platform, 300. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects. Unless otherwise specified, the term "connection" as used herein can refer to a direct connection or an indirect connection, i.e., a connection through an intermediate object.

[0017] Furthermore, it should be understood that the orientations or positional relationships indicated by terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" in this document are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "first" and "second" in this document are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0018] To address the problems existing in the prior art, embodiments of this utility model provide a wafer grinding head, as shown in the reference. Figure 1 and Figure 2 As shown, the wafer polishing head includes a polishing head body 1, which has a disc-shaped structure. The bottom of the polishing head body 1 is divided into N polishing pressure regions and N polishing gap regions. Each polishing pressure region is provided with a pressure film 11, and the bottom of each polishing gap region is provided with a gap film 12. The pressure film 11 and the gap film 12 independently control the pressure. When polishing the wafer, the pressure film 11 and the gap film 12 cooperate to apply pressure to the wafer. A fixing ring 2 is located at the bottom edge of the polishing head body 1 to fix the wafer.

[0019] In this embodiment, by dividing the bottom of the grinding head body 1 into N grinding pressure regions and N grinding gap regions, and by providing pressure films 11 in the N grinding pressure regions and gap films 12 at the bottom of each grinding gap region, the pressure inside the pressure films 11 and gap films 12 is independently controlled to ensure that the pressure applied by the grinding head to the wafer surface is uniform and continuous, thereby improving the effect of wafer surface planarization.

[0020] In some specific embodiments, the bottom of the grinding head body 1 has a groove structure. The groove structure is circular, and the N grinding pressure regions and N grinding gap regions are all located within the groove structure. The N grinding pressure regions are all concentrically arranged with the grinding head body 1, so that the N pressure films 11 are all concentric with the grinding head body 1. The diameter of the N pressure films 11 gradually increases from the center to the edge of the grinding head body 1. One grinding gap region is located between the outermost grinding pressure region and the fixing ring 2, and the remaining N-1 grinding gap regions are located between two adjacent grinding pressure regions.

[0021] In this embodiment, by setting the grinding gap region between the N grinding pressure regions and setting the independently controlled gap film 12 at the bottom of the grinding gap region, the problem of uneven and discontinuous pressure applied to the wafer surface caused by the low interface pressure between the two regions in the existing design is overcome, thereby improving the effect of wafer surface planarization.

[0022] In some embodiments, each of the pressure diaphragms 11 is provided with an air supply hole 111, which is connected to an external pressure control device via a pipeline.

[0023] Furthermore, the grinding head also includes N isolation rings 13, each corresponding to one of the N gap films 12. Each isolation ring 13 is a hollow annular structure with an air supply channel. One isolation ring 13 is located between the outermost pressure film 11 and the fixing ring 2, connecting the outermost pressure film 11 to the fixing ring 2. The remaining N-1 isolation rings 13 are respectively disposed in the corresponding grinding gap regions, connecting two adjacent pressure films 11. Each isolation ring 13 is connected to the corresponding gap film 12 through the air supply channel, and the isolation ring 13 is also connected to an external pressure control device through a pipeline.

[0024] In some embodiments, the gap film 12 is an annular sheet structure. The outermost edge of the gap film 12 is sealed to the inner wall of the fixing ring 2, and its inner edge is sealed to the bottom of the outermost pressure film 11. The gap film 12 located between two adjacent pressure films 11 has its outer edge sealed to the bottom of the adjacent outer pressure film 11, and its inner edge sealed to the bottom of the adjacent inner pressure film 11.

[0025] It is understood that the outer pressure film 11 and the inner pressure film 11 mentioned in this embodiment are determined relative to the position of the gap film 12.

[0026] In some embodiments, the pressure diaphragm 11 is a hollow diaphragm, and the air supply hole 111 is formed on the top of the hollow diaphragm. N pressure diaphragms 11 are connected by the partition ring 13 to fill the groove structure at the bottom of the grinding head body 1.

[0027] In some embodiments, the grinding head body 1 has a pressure chamber 14 at its top. The pressure chamber 14 is provided with a first delivery pipe and a second delivery pipe. The first delivery pipe is connected to the pressure diaphragm 11 through the air supply hole 111, and the second delivery pipe is connected to the gap diaphragm 12 through the air supply channel on the isolation ring 13. Both the first delivery pipe and the second delivery pipe are connected to an external pressure control device through pipelines.

[0028] In this embodiment, by setting up independent first and second delivery pipes to supply air to the pressure diaphragm 11 and the gap diaphragm 12 respectively, the pressure of the pressure diaphragm 11 and the gap diaphragm 12 can be independently controlled.

[0029] It should be noted that the specific configuration and arrangement of the first and second conveying pipes are not limited here, as long as the first and second conveying pipes can independently supply air to the pressure diaphragm 11 and the gap diaphragm 12 respectively.

[0030] In some embodiments, the value of N ranges from 3 to 8.

[0031] In this embodiment, N is 4, meaning that the number of pressure films 11 and gap films 12 in this embodiment are both 4.

[0032] In some embodiments, the value of N can be 3, 5, 6, 7 or 8, which can be set according to actual production requirements, and will not be elaborated here.

[0033] In one embodiment provided in this application, a chemical mechanical grinding apparatus is provided, with reference to... Figure 3 As shown, the device includes a polishing platform 200, a polishing pad 300, and a polishing head 100 as described in the above embodiment. The polishing pad 300 is disposed on the polishing platform 200; the polishing head 100 is disposed corresponding to the polishing pad 4 and is used to press the wafer against the polishing pad 4 for polishing.

[0034] In this embodiment, by applying pressure to the wafer using the grinding head 100, the effect of wafer surface planarization is improved.

[0035] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of this application should be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A wafer grinding head, characterized in that, include: The grinding head body has N grinding pressure areas and N grinding gap areas at the bottom. Each grinding pressure area is provided with a pressure film, and the bottom of each grinding gap area is provided with a gap film. The pressure film and the gap film are independently controlled. Both the pressure film and the gap film are used to apply pressure to the wafer. A retaining ring is located at the bottom edge of the grinding head body and is used to fix the wafer.

2. The wafer grinding head according to claim 1, characterized in that, All N pressure films are concentric with the grinding head body, and the diameter of the N pressure films gradually increases from the center to the edge of the grinding head body; One of the grinding gap regions is located between the outermost grinding pressure region and the fixing ring, and the remaining N-1 grinding gap regions are located between two adjacent grinding pressure regions.

3. The wafer grinding head according to claim 1, characterized in that, Each of the pressure diaphragms is provided with an air supply hole, which is connected to an external pressure control device via a pipeline.

4. The wafer grinding head according to claim 1, characterized in that, It also includes N partition rings, each partition ring having an air supply channel, and each air supply channel being connected to the corresponding gap membrane; One of the partition rings is located between the outermost pressure film and the fixing ring, and is used to connect the outermost pressure film and the fixing ring. The remaining N-1 partition rings are respectively disposed in the corresponding grinding gap regions to connect two adjacent pressure films.

5. The wafer grinding head according to claim 4, characterized in that, The gap film has an annular sheet structure; The outer edge of the outermost gap membrane is sealed to the inner wall of the fixing ring, and the inner edge is sealed to the bottom of the outermost pressure membrane. The gap membrane located between two adjacent pressure membranes has its outer side sealed to the bottom of one of the adjacent pressure membranes and its inner side sealed to the bottom of the other adjacent pressure membrane.

6. The wafer grinding head according to claim 3, characterized in that, The pressure diaphragm is a hollow diaphragm, and the air supply hole is located at the top of the hollow diaphragm.

7. The wafer grinding head according to claim 3, characterized in that, The grinding head body has a pressure chamber at its top; The pressure chamber is provided with a first delivery pipe and a second delivery pipe. The first delivery pipe is connected to the air supply hole, and the second delivery pipe is connected to the gap membrane. Both the first delivery pipe and the second delivery pipe are connected to an external pressure control device through pipelines.

8. The wafer grinding head according to claim 7, characterized in that, The bottom of the grinding head body is a groove structure, and both the pressure film and the gap film are disposed within the groove structure.

9. The wafer grinding head according to claim 1, characterized in that, The value of N ranges from 3 to 8.

10. A chemical mechanical grinding apparatus, characterized in that, Includes a grinding platform, a grinding pad, and a grinding head as described in any one of claims 1 to 9; The grinding pad is disposed on the grinding platform; The grinding head is disposed corresponding to the grinding pad and is used to press the wafer against the grinding pad.

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