CN212824753U

CN212824753U - Sapphire wafer and sapphire dresser for chemical mechanical polishing pad

Info

Publication number: CN212824753U
Application number: CN202020619775.8U
Authority: CN
Inventors: 徐良; 杨新鹏; 郑小琳; 蓝文安; 刘建哲; 余雅俊; 夏建白; 李京波; 黄仕华; 占俊杰
Original assignee: Zhejiang Bolante Semiconductor Technology Co ltd
Current assignee: Jinhua Bolante New Material Co.,Ltd.
Priority date: 2020-04-22
Filing date: 2020-04-22
Publication date: 2021-03-30
Anticipated expiration: 2030-04-22

Abstract

The utility model provides a sapphire wafer and sapphire dresser that is used for chemical mechanical polishing pad, this sapphire wafer include sapphire wafer body and grit, the grit regular arrangement is in on the sapphire wafer body, and sapphire wafer body with the grit structure as an organic whole. A plurality of abrasive grains with specific shapes are etched on the surface of the sapphire wafer, and the arrangement of the abrasive grains has high orderliness so as to improve the dressing effect.

Description

Sapphire wafer and sapphire dresser for chemical mechanical polishing pad

Technical Field

The utility model relates to a semiconductor wafer preparation technical field, concretely relates to sapphire wafer and sapphire trimmer.

Background

As the ultra-large scale integrated circuit is developed to a highly integrated and multi-layered wiring structure, the process of flatness of the wafer surface is becoming more and more important. Chemical Mechanical Polishing (CMP) techniques, which have the advantages of high planarization, good uniformity, high material removal efficiency, and the like, have become the main process for high-precision planarization of semiconductor materials. In the polishing process, the semiconductor wafer is pressed on a flexible polishing pad adhered on a rigid polishing flat disc and is polished under the action of polishing liquid; the surface of the polishing pad is rough or has pores, so that the polishing liquid stays therein to enhance the polishing rate and the polishing quality. However, as the polishing operation progresses, gaps or pores on the surface of the polishing pad are quickly filled with the debris, so that the surface is glazed by polishing slip, and the required polishing effect cannot be achieved. Therefore, the surface condition of the polishing pad plays a decisive role in the polishing effect.

In order to activate the surface condition of the polishing pad, maintain a constant polishing effect, and extend its service life, it is necessary to regularly dress the pad using a dresser. At present, diamond polishing pad dressers are mainly used in the market, and diamond particles are firmly fixed by matrix materials through methods such as electroplating, chemical brazing, metal sintering, chemical vapor deposition and the like. If the diamond particles fall off during the polishing process, the surface of the polished wafer can be scratched and damaged; furthermore, the arrangement order of the diamonds can have a great influence on the dressing effect. With the upgrading of technology, the existing diamond dresser greatly reduces the probability of diamond falling off, but still has the falling off risk.

SUMMERY OF THE UTILITY MODEL

The main object of the utility model is to provide a sapphire wafer and sapphire dresser that is used for chemical mechanical polishing pad, this sapphire wafer body surface erosion goes out the grit of a plurality of specific shapes to the range of grit has high orderliness, in order to promote the effect of repairing, in order to solve among the prior art because diamond particles drop the technical problem who is damaged by polishing wafer surface fish tail that leads to.

In order to achieve the above object, according to a first aspect of the present invention, a sapphire wafer is provided.

The sapphire wafer comprises a sapphire wafer body and abrasive particles, wherein the abrasive particles are regularly arranged on the sapphire wafer body, and the sapphire wafer body and the abrasive particles are of an integral structure.

Further, the bottom diameter of the abrasive particles is 100-300 mu m, and the height of the abrasive particles is 50-300 mu m; the distance between two adjacent abrasive particles is 100-600 mu m.

Further, the shape of the abrasive particles is frustum-like, conical-like or triangular pyramidal.

Further, the abrasive particles are distributed on the surface of the sapphire wafer body.

Furthermore, the abrasive particles are distributed along the circumferential edge of the sapphire wafer body, and a first flow guide groove arranged in a sealing mode is formed in the middle of the sapphire wafer body.

Furthermore, the abrasive particles are distributed along the circumferential edge of the sapphire wafer body, and a second diversion trench communicated with the edge of the sapphire wafer body is formed in the middle of the sapphire wafer body.

In order to achieve the above object, according to a second aspect of the present invention, there is provided a sapphire dresser for a chemical mechanical polishing pad.

The sapphire dresser for the chemical mechanical polishing pad comprises a supporting seat and the sapphire wafer, wherein the sapphire wafer is connected to the supporting seat in a body mode, and the sapphire wafer and the supporting seat are arranged in a concentric circle mode.

Furthermore, the bottom of the supporting seat is provided with a positioning hole and a screw hole which are used for being connected with special trimming equipment.

The utility model has the advantages that:

(1) the utility model provides an abrasive particle size and distribution have diversified, adjust nimble characteristics.

(2) The polishing pad dresser disk surface of the utility model is made of sapphire materials integrally, thus avoiding the problem that diamond particles of the traditional diamond dresser fall off; meanwhile, the size and distribution of the abrasive particles are high in adjustment flexibility, high-precision ordered arrangement can be achieved, and the finishing effect is improved.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1a to 1c are top views of a sapphire dresser in an embodiment of the present invention;

fig. 2 a-2 b are side views of a sapphire dresser in an embodiment of the present invention;

fig. 3 is a bottom view of a sapphire conditioner in an embodiment of the present invention;

fig. 4 is a schematic view illustrating an assembly of a sapphire wafer and a supporting base according to an embodiment of the present invention;

fig. 5a to 5h are schematic flow charts illustrating a method for manufacturing a sapphire wafer having abrasive grains according to an embodiment of the present invention.

In the figure:

1. a sapphire wafer body; 101. abrasive particles; 102. a first diversion trench; 103. a second guiding gutter; 2. a supporting seat; 3. positioning holes; 4. a screw hole; 5. a silicon oxide layer; 51. a silicon oxide mask pattern; 6. a photoresist layer; 61. and (5) photoresist pattern.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The utility model discloses a sapphire wafer, as shown in figures 1 a-1 c, abrasive grains 101 are regularly arranged on a sapphire wafer body 1; and the sapphire wafer body 1 and the abrasive grains 101 are of an integral structure.

In the above embodiment, the abrasive grains 101 distributed on the sapphire wafer body 1 are integrally made of the sapphire wafer body 1, so that the problem of falling off of diamond grains of a traditional diamond dresser is solved; meanwhile, the abrasive particles 101 are high in adjustment flexibility in specification and distribution, high-precision ordered arrangement can be achieved, and the finishing effect is improved. And the formation of the abrasive grains 101 on the sapphire wafer body 1 can be achieved by wet etching the sapphire body 1.

As another embodiment of the present invention, the bottom diameter of the abrasive grains 101 is in the range of 100 to 300 μm, preferably 200 μm.

As another embodiment of the present invention, the height of the abrasive grains 101 is in the range of 50 to 300 μm, preferably 100 μm.

As another embodiment of the present invention, the distance between two adjacent abrasive grains 101 is within the range of 100 to 600 μm, preferably 250 μm.

As another embodiment of the present invention, the shape of the abrasive grains 101 may be a truncated cone-like shape, a conical cone-like shape or a triangular cone-like shape, and the size and shape can be adjusted by itself according to the requirement, so that the abrasive grains have the characteristics of diversification, flexibility in adjustment, etc.

The utility model provides an abrasive particle 101 is multiple mode of arranging on sapphire wafer body 1, specifically shows three kinds of modes of arranging.

The first arrangement is shown in fig. 1a, and the entire surface of the sapphire wafer body 1 is filled with abrasive grains 101, and the side view thereof is shown in fig. 2 a.

The second arrangement is as shown in fig. 1b, the abrasive grains 101 are distributed along the circumferential edge of the sapphire wafer body 1, the abrasive grains 101 are not arranged in the middle of the sapphire wafer body 1, a closed first guiding gutter 102 is formed, and the side view of the first guiding gutter is as shown in fig. 2 b.

The third arrangement is as shown in fig. 1c, the abrasive grains 101 are distributed along the circumferential edge of the sapphire wafer body 1, a second guiding groove 103 communicating with the edge of the sapphire wafer body 1 is formed in the middle of the sapphire wafer body 1, the second guiding groove 103 is in a fan-shaped structure, and the side view of the second guiding groove is as shown in fig. 2 b.

The utility model also discloses a sapphire dresser for chemical mechanical polishing pad, as shown in figure 4, sapphire dresser includes supporting seat 2 and above-mentioned sapphire wafer, sapphire wafer is as the quotation of dresser, and sapphire wafer body 1 bonds for concentric circles formula with supporting seat 2, forms complete dresser, specifically can bond through liquid bonding wax or glue; preferably a liquid bonding wax bond. The supporting seat 2 is made of stainless steel, and the supporting seat 2 can be repeatedly used.

As shown in fig. 3, a positioning hole 3 and a screw hole 4 are provided at the bottom of the support base 2 for fixing the support base 2 to a dedicated dressing disk or a dressing apparatus.

The utility model also discloses a preparation method of sapphire wafer with grit, this sapphire wafer's preparation method includes following step:

s100, referring to fig. 5a, a sapphire wafer body 1 with high flatness and cleanliness is provided.

S200, referring to FIG. 5b, uniformly depositing silicon oxide (SiO) on the surface of the sapphire wafer body 1 by using a chemical vapor deposition process₂) A layer 5; the thickness of the silicon oxide layer 5 is in the range of 0.1 to 5 μm.

S300, referring to fig. 5c, applying a photoresist on the upper surface of the silicon oxide layer 5 by using a spin coating process to form a photoresist layer 6; the thickness of the photoresist layer 6 is in the range of 1.5 to 2.5 μm, preferably 2.0 μm.

S400, referring to fig. 5d, forming a photoresist pattern 61 consistent with an exposure mask by a photolithography process, specifically, by exposure and development; the specification of the exposure mask plate can be designed according to the dressing effect of the polishing pad.

S500, referring to FIG. 5e, a wet etching process is adopted, specifically, an etching solution is adopted to remove the silicon oxide layer 5 which is not shielded by the photoresist pattern 61, so as to form a morphology layer formed by overlapping photoresist and silicon oxide; the etching solution is a mixed solution (BOE solution) of hydrofluoric acid and ammonium fluoride, and the mass percentage of the hydrofluoric acid to the ammonium fluoride is 1: 5.

s600, referring to fig. 5f, removing the photoresist pattern 61 with an organic solvent to obtain an exposed silicon oxide mask pattern 51; wherein the organic solvent is acetone.

S700, referring to fig. 5g, performing an erosion process on the sapphire wafer body 1 by using the silicon oxide mask pattern 51 as a mask, specifically: the sapphire wafer body 1 is put into high-temperature mixed solution of concentrated sulfuric acid and concentrated phosphoric acid for erosion and is corroded by SiO₂The part shielded by the mask layer is not easy to be corroded to form a graph as shown in fig. 5 g; wherein the mass percentage of the concentrated sulfuric acid to the concentrated phosphoric acid is 3-5: 1, the temperature is 200-330 ℃, and can be adjusted according to the erosion effect.

S800, referring to fig. 5h, a plurality of abrasive grains 101 with a specific shape and regular arrangement are formed on the sapphire wafer body 1 by a cleaning process, specifically, removing the silicon oxide mask pattern 51 with a BOE solution.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A sapphire wafer is characterized by comprising a sapphire wafer body (1) and abrasive particles (101), wherein the abrasive particles (101) are regularly arranged on the sapphire wafer body (1), and the sapphire wafer body (1) and the abrasive particles (101) are of an integral structure;

the abrasive particles (101) are distributed along the circumferential edge of the sapphire wafer body (1), and a first guide groove (102) which is arranged in a sealing mode or a second guide groove (103) communicated with the edge of the sapphire wafer body (1) is formed in the middle of the sapphire wafer body (1).

2. The sapphire wafer according to claim 1, wherein the abrasive grains (101) have a base diameter of 100 to 300 μm and a height of 50 to 300 μm; the distance between two adjacent abrasive grains (101) is 100-600 mu m.

3. Sapphire wafer according to claim 1, characterized in that the abrasive particles (101) have the shape of a truncated cone-like, a cone-like or a triangular pyramid.

4. A sapphire dresser for a chemical mechanical polishing pad, comprising a support base (2) and a sapphire wafer according to any one of claims 1 to 3, wherein the sapphire wafer body (1) is attached to the support base (2), and the sapphire wafer body (1) and the support base (2) are arranged in concentric circles.

5. The sapphire dresser for a chemical mechanical polishing pad according to claim 4, wherein the bottom of the support base (2) is provided with positioning holes (3) and screw holes (4) for connecting with a dedicated dressing device.