TWM634772U - Elastic film for use in chemical mechanical grinding device - Google Patents

Abstract

The elastic film of the invention is used with a grinding head, which includes a wafer contact portion and an annular convex portion connected to the wafer contact portion, the elastic film is fixed on the grinding head with the annular convex portion, so that the gap between the elastic film and the grinding head A pressure chamber is formed. In addition, the contact portion of the wafer has multiple areas with different hardness or materials. The parameters such as the shape, size, distribution position, and arrangement density of the aforementioned areas with different hardness or materials can be changed as necessary according to actual needs, so that the elastic film The pressure exerted by the wafer contact portion on the wafer can be properly adjusted, thereby improving the uniformity of chemical mechanical polishing.

Description

Elastic Membranes for Chemical Mechanical Abrasive Devices

This creation is related to a chemical mechanical polishing device, in particular to an elastic membrane used in a chemical mechanical polishing device.

During Chemical-Mechanical Planarization (CMP), the wafer is placed between the polishing head and the polishing pad, and the gas is injected into the polishing head. At this time, the film made of elastic material will be pushed by the gas pressure. Squeeze and expand, and exert pressure on the wafer below it. In this way, the grinding head can drive the wafer to rotate relative to the polishing pad, so that mechanical grinding will occur between the wafer and the polishing pad, and at the same time, the polishing slurry will be in contact with the wafer. The layer of material to be planarized on the circle undergoes chemical grinding.

However, in the aforementioned conventional technology, the gas injected into the grinding head will form a uniform pressure, but in order to achieve better grinding uniformity, the pressure of each area of the wafer needs to be adjusted, thereby improving the yield of subsequent processes and the components to be produced. reliability.

The main purpose of the present invention is to provide an elastic membrane for a chemical mechanical polishing device, which can improve the uniformity of chemical mechanical polishing.

In order to achieve the above main purpose, the elastic film of the present invention includes a wafer contact portion and an annular convex portion. The wafer contact portion is disk-shaped, and the wafer contact portion has a first surface and a second surface facing away from the first surface, and the wafer contact portion contacts a wafer with the second surface; the wafer contact portion contacts a wafer with the second surface; The annular convex portion is integrally connected to the first surface of the contact portion for fixing with a grinding head, so that a pressure chamber is formed between the elastic film and the grinding head, wherein the wafer contact portion has a plurality of Areas of different hardness or material.

It can be seen from the above that when the gas is injected into the pressure chamber, the elastic membrane will be pushed and expanded by the gas pressure, and exert pressure on the wafer below it. Parameters such as size, distribution position, and arrangement density can be changed as necessary according to actual needs, so that the elastic film exerts an appropriate pressure on the wafer through the contact portion of the wafer, thereby improving the uniformity of chemical mechanical polishing.

Preferably, the wafer contact part is made of materials of different hardness or material (such as polytetrafluoroethylene, stainless steel, aluminum or other hard plastics that can be combined with elastic materials such as rubber and silicon rubber) in an integrated manner, The wafer contact portion has multiple regions of different hardness or material.

Preferably, the wafer contact portion has a central region, a middle region adjacent to the central region and a peripheral region adjacent to the middle region, the central region, the middle region and the peripheral region have different hardness or material.

Preferably, a plurality of materials of different hardness or material are buried inside the wafer contact part, such as polytetrafluoroethylene, stainless steel, aluminum or other hard plastics that can be combined with elastic materials such as rubber and silicone, so that the wafer contacts The top has multiple regions of different hardness or material.

The detailed structure, characteristics, assembly or usage of the elastic membrane used in the chemical mechanical polishing device provided by the present creation will be described in the detailed description of the following embodiments. However, those with ordinary knowledge in the field of this creation should be able to understand that these detailed descriptions and the specific embodiments listed for implementing this creation are only used to illustrate this creation, and are not used to limit the scope of patent applications for this creation.

The applicant hereby explains that in the entire specification, including the embodiments described below and the claims of the scope of the patent application, the nouns related to direction are based on the directions in the drawings. Secondly, in the embodiments and drawings to be described below, the same component numbers represent the same or similar components or their structural features.

Please refer to Fig. 1 and Fig. 2, the elastic film 10 of the first embodiment of the present invention comprises a disc-shaped wafer contact portion 20, the wafer contact portion 20 has a plurality of regions with different hardness or materials, in this embodiment Among them, the wafer contact portion 20 is made of materials with different hardness or materials in an integral manner. Furthermore, as shown in FIGS. 2 and 3 , the wafer contact portion 20 has a central area 22, an intermediate area 24 adjacent to the central area 22, and a peripheral area 26 adjacent to the intermediate area 24. The central area 22. The middle area 24 and the peripheral area 26 are made of materials with different hardness or materials, such as polytetrafluoroethylene, stainless steel, aluminum or other hard plastics that can be combined with elastic materials such as rubber and silicone, so that the central area 22, The middle region 24 and the peripheral region 26 have different hardnesses or materials. However, it is worth mentioning that the central region 22, the middle region 24 and the peripheral region 26 have the same thickness, and there is no certain order in terms of hardness or material, and the hardness or material size of the three can be adjusted according to actual needs. Variety. In addition, in this embodiment, the central area 22 is circular, and the middle area 24 and the peripheral area 26 are both ring-shaped, but they are not limited to the aforementioned shapes.

In addition, the wafer contact portion 20 further has a first surface 28 and a second surface 30 facing away from the first surface 28. The elastic membrane 10 of the first embodiment of the present invention further includes four annular protrusions 32, 34, 36. , 38, the annular protrusions 32, 34, 36, 38 are connected to the first surface 28 of the wafer contact portion 20 in an integrated manner, and the annular protrusions 32, 34, 36, 38 are relatively to the wafer The center of the contact portion 20 is arranged at intervals from the outside to the inside. It is worth mentioning here that the shapes and heights of the annular protrusions 32, 34, 36, and 38 can be changed as necessary according to actual needs. limited.

In actual use, as shown in FIG. 4 , the outer peripheral surface of the outermost annular convex portion 32 of the elastic membrane 10 leans against a restraint ring 40, and the elastic membrane 10 is assembled on a top end of the outermost annular convex portion 32. The grinding head 42, the grinding head 42 has an inner ring wall 44 and an outer ring wall 46 arranged on the inner ring wall 44, the inner ring wall 44 of the grinding head 42 abuts against the first wafer contact portion 20 of the elastic film 10 Surface 28 and between the two innermost annular protrusions 36, 38, the outer ring wall of the grinding head 42 is located between the outermost two annular protrusions 32, 34, so that the elastic membrane 10 and the grinding head 42 Three pressure chambers 48 are formed between the inner, middle and outer. In addition, the elastic film 10 contacts a wafer 50 with the second surface 30 of the wafer contact portion 20 , and the wafer 50 is placed on a polishing pad 52 . When gas is injected into the three pressure chambers 48, the wafer contact portion 20 of the elastic film 10 will be pushed and expanded by the gas pressure, and will exert pressure on the wafer 50 below it, because the wafer contact portion 20 has A plurality of areas with different hardness or materials, the parameters of the aforementioned areas can be changed according to the actual needs in terms of shape and size, and then the gas pressure changes in the three pressure chambers 48 make the elastic film 10 contact with the wafer The pressure exerted by the part 20 on the wafer 50 can be evenly distributed, thereby improving the uniformity of chemical mechanical polishing.

On the other hand, the structure of the elastic membrane can vary in various ways. Please refer to FIG. 5 to FIG. 7, the wafer contact portion 62 provided by the elastic film 60 of the second embodiment of the present invention is embedded with a plurality of materials 68 with different hardness or materials, such as polytetrafluoroethylene, stainless steel, etc. , aluminum or other hard plastics that can be combined with elastic materials such as rubber and silicone, so that the wafer contact portion 62 has multiple block-shaped regions with different hardness or materials. Furthermore, in this embodiment, the aforementioned materials 68 are mainly located in the central area 64 and the peripheral area 66, wherein the materials 68 distributed in the central area 64 have different geometric shapes, and the materials 68 distributed in the peripheral area 66 are in the form of rings. However, in fact, the parameters such as the shape, size, distribution position and arrangement density of the aforementioned materials 68 can be changed as necessary according to actual needs, and are not limited to the aspects drawn in this embodiment. In this way, the wafer contact portion 62 is used to embed a plurality of materials with different hardness or materials inside, and with the change of gas pressure in the three pressure chambers 48, the elastic film 60 exerts a force on the wafer 50 through the wafer contact portion 62 . The pressure can be evenly distributed, thereby improving the uniformity of chemical mechanical grinding.

10: Elastic film 20: Wafer contact part 22: Central area 24: Middle area 26: Surrounding area 28: First Surface 30: second surface 32: Annular convex part 34: Annular convex part 36: Annular convex part 38: Annular convex part 40: restraint ring 42: Grinding head 44: inner ring wall 46: Outer ring wall 48: Pressure chamber 50: Wafer 60: elastic film 62: Wafer contact part 64: Central area 66: Surrounding area 68:Material

Fig. 1 is the plan view of the elastic membrane of the first embodiment of the present invention. Fig. 2 is a cross-sectional view along line 2-2 in Fig. 1 . FIG. 3 is a partially enlarged view of FIG. 2 . Fig. 4 is a partial cross-sectional view of the elastic film used in conjunction with the grinding head in the first embodiment of the invention. Fig. 5 is a top view of the elastic membrane of the second embodiment of the present invention. Fig. 6 is a cross-sectional view of Fig. 5 along line 6-6. Fig. 7 is a cross-sectional view along line 7-7 in Fig. 5 .

10: Elastic film

20: Wafer contact part

22: Central area

24: Middle area

26: Surrounding area

28: First Surface

30: second surface

32: Annular convex part

34: Annular convex part

36: Annular convex part

38: Annular convex part

Claims (6)

An elastic membrane used in a chemical mechanical polishing device, which is assembled on a grinding head, the elastic membrane includes a wafer contact portion and an annular convex portion, the wafer contact portion is disc-shaped, and the wafer contact portion It has a first surface and a second surface facing away from the first surface, the annular convex part is integrally connected to the first surface of the contact part, and the annular convex part is used to fix the grinding head so that the elastic A pressure chamber is formed between the membrane and the grinding head, wherein the wafer contact portion has a plurality of regions of different hardness or material. The elastic film for chemical mechanical polishing device according to claim 1, wherein the wafer contact part is made of materials with different hardness or material. The elastic film for a chemical mechanical polishing device according to claim 2, wherein the wafer contact portion has a central area, an intermediate area adjacent to the central area, and a peripheral area adjacent to the intermediate area, The central area, the middle area and the peripheral area have different hardness or material. The elastic membrane used in a chemical mechanical polishing device according to claim 3, wherein the central area is circular, and both the central area and the peripheral area are ring-shaped. The elastic film for chemical mechanical polishing device according to claim 1, wherein a plurality of materials with different hardness or material are buried inside the wafer contact portion. The elastic film for chemical mechanical polishing device according to claim 5, wherein the materials are in the shape of a circle, a ring or a block.

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