Wafer Polishing Locating Ring and Chemical Mechanical Polishing Device

Abstract

This application provides a wafer polishing locating ring. The wafer polishing locating ring includes a ring body and a plurality of grooves formed in the ring body. The ring body is a circular ring body and includes an inner sidewall and an outer sidewall. The grooves run through the outer sidewall and inner sidewall of the ring body. An included angle between a sidewall and a bottom of each groove is an acute angle. This application solves the problem of short service life of the existing wafer polishing locating ring.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority to Chinese patent application No. 202310110992.2, filed on Feb. 14, 2023, the disclosure of which is incorporated herein by reference in entirety.

TECHNICAL FIELD

This application relates to the field of integrated circuit manufacturing, in particular to a wafer polishing locating ring and a chemical mechanical polishing device.

BACKGROUND

With the increasing reduction of semiconductor device size and the sharp increase in device density, multi-layer wiring technology has emerged. However, although the use of multi-layer wiring technology can improve the integration density of devices, it causes excessive fluctuations on the wafer surface, leading to focusing problems in the photolithography process and a decrease in the consistency of line width across the entire wafer. Therefore, it is necessary to planarize the irregular wafer surface. Chemical Mechanical Polishing (CMP) has become the best method for global planarization and an indispensable process in the entire wafer manufacturing process.

At present, the industry generally uses a chemical mechanical polishing machine to complete the chemical mechanical polishing process. The polishing module of the existing chemical mechanical polishing machine mainly includes a polishing disc, a polishing pad, a polishing head, a wafer polishing locating ring, and a rubber diaphragm. During the polishing process, the wafer is placed inside the wafer polishing locating ring, and the polishing machine transmits precise pressure to the rubber diaphragm of the polishing head, controlling the contact between the wafer and the polishing pad through the above method. When the wafer polishing locating ring and the wafer move relative to the polishing pad located below them, the polishing fluid flows into the locating ring and the wafer along the groove opening in the bottom surface of the wafer polishing locating ring, thus achieving surface planarization of the wafer under the action of the polishing fluid.

Throughout the polishing module of the chemical mechanical polishing machine, the consumables for daily maintenance include a polishing fluid filter, a polishing pad, a diamond disc, a polishing head, etc. The service life of the polishing head is limited by the remaining height of the groove in the wafer polishing locating ring, because the remaining height of the groove can ensure that the polishing fluid flows into the wafer through the opening. Moreover, in daily operations, we usually convert the wear height of the groove in the wafer polishing locating ring into the number of hours or pieces corresponding to the wafer polishing locating ring. Therefore, it is necessary to extend the service life of the groove in the wafer polishing locating ring as much as possible.

BRIEF SUMMARY

In view of the disadvantages of the existing technology mentioned above, the purpose of this application is to provide a wafer polishing locating ring for solving the problem that the service life of the existing wafer polishing locating ring is short.

In order to achieve the above purposes and other purposes, this application provides a wafer polishing locating ring, including a ring body and a plurality of grooves formed in the ring body, wherein the ring body is a circular ring body and includes an inner sidewall and an outer sidewall, the grooves run through the outer sidewall and inner sidewall of the ring body, and an included angle between a sidewall and a bottom of each groove is an acute angle.

Exemplarily, two sidewalls of each groove are in parallel.

Exemplarily, the vertical height of each groove is 3 mm-4 mm; the horizontal width of each groove is 3 mm-4 mm.

Exemplarily, the vertical height of each groove is 3 mm-3.2 mm; the horizontal width of each groove is 3 mm-3.2 mm.

Exemplarily, edges of the grooves close to the inner sidewall and the outer sidewall are in an arc shape.

Exemplarily, the angle of the arc shape is 30°-75°.

Exemplarily, the grooves are inclined clockwise from the inner sidewall to the outer sidewall.

Exemplarily, the material of the wafer polishing locating ring includes polyphenylene sulfide, polyether ether ketone, or semi-crystalline thermoplastic polymer.

This application further provides a chemical mechanical polishing device, including a polishing disc, a polishing pad adhered to the polishing disc, a polishing head, and the wafer polishing locating ring described above, wherein the wafer polishing locating ring is provided on the polishing head.

Exemplarily, the chemical mechanical polishing device further includes a rubber diaphragm, and the rubber diaphragm is provided on the polishing head.

As described above, by adopting the wafer polishing locating ring and the chemical mechanical polishing device provided in this application, the service life of the wafer polishing locating ring is prolonged by setting the opening angle of the grooves in the ring body of the wafer polishing locating ring to an acute angle. Moreover, other consumables (such as rubber diaphragm) used in the polishing head and the wafer polishing locating ring need to be replaced simultaneously. Therefore, while the service life of the wafer polishing locating ring is prolonged, the use time of other consumables used in the polishing head can also be synchronously prolonged, thus reducing the cost and time of maintenance of the chemical mechanical polishing device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a top schematic diagram of a wafer polishing locating ring according to this application.

FIG. 2 illustrates a sectional structural schematic diagram of a groove in a wafer polishing locating ring according to this application.

FIG. 3 illustrates a partial schematic diagram of a wafer polishing locating ring according to this application.

FIG. 4 illustrates a schematic diagram of a chemical mechanical polishing device according to this application.

DESCRIPTION OF REFERENCE SIGNS

• • 10—wafer polishing locating ring; 11—ring body; 12—groove; 12a—edge; 111—inner sidewall; 112—outer sidewall; 20—polishing fluid; 30—wafer; 40—polishing pad; 50—polishing head; 60—polishing disc; 70—rubber diaphragm

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments of this application will be described below through specific examples. Those skilled in the art can easily understand the other advantages and effects of this application from the content disclosed in the description. This application may also be implemented or applied through other different specific embodiments, and the details in the description may also be modified or changed based on different perspectives and applications without departing from the spirit of this application.

Please refer to FIG. 1 to FIG. 4. It should be noted that the drawings provided in the embodiments are only used for schematically describing the basic concept of this application. Although the drawings only illustrate the components related to this application and are not drawn based on the actual number, shape, and size of the components during implementation. The form, number, and scale of each component during actual implementation may be freely changed, and the layout of the component may also be more complex.

Referring to FIG. 1, this embodiment provides a wafer polishing locating ring 10. The wafer polishing locating ring 10 includes a ring body 11 and a plurality of grooves 12 formed in the ring body 11. The ring body 11 is a circular ring body and includes an inner sidewall 111 and an outer sidewall 112. The grooves 12 run through the outer sidewall 112 and inner sidewall 111 of the ring body 11. An included angle between a sidewall and a bottom of each groove 12 is an acute angle.

In this embodiment, the included angle between the sidewall and the bottom of the groove 12 is regarded as opening angle θ. In a case that the opening angle θ is an acute angle, the service life of the polishing locating ring 10 can be prolonged. Specifically, referring to FIG. 2, in a case that the opening angle θ is 30°, the height of the groove 12 in the vertical direction is H, the remaining height required in the vertical direction is H1, the length of its sidewall is L, and L=H/Sin θ. In a case that the opening angle θ is 90°, the height H of the groove 12 in the vertical direction is equal to the length L of the sidewall of the groove 12, and the remaining height required in the vertical direction is still H1. In the case that the opening angle θ is 90°, the height of loss available in the vertical direction ΔH=H−H1. In a case that the lost height is the same when the opening angle θ is 30°, then the length of the sidewall of the groove 12 that can be lost ΔL=(H−H1)/Sin θ. And ΔL/ΔH=[(H−H1)/Sin θ]/(H−H1)=1/Sin θ=2. Accordingly, it can be seen that when the opening angle is 30°, the length of the sidewall of the groove 12 that can be lost is longer, thus prolonging the service life of the wafer polishing locating ring 10 by two times.

The number of the grooves 12 may be set as needed. Exemplarily, in this embodiment, the number of the grooves 12 is 18.

Specifically, two sidewalls of each groove are in parallel.

In this embodiment, in a case that the two sidewalls of each groove 12 are in parallel, the effect of polishing fluid 20 flowing into the wafer 30 through the groove 12 is better.

Specifically, the vertical height of each groove is 3 mm-4 mm; the horizontal width of each groove is 3 mm-4 mm.

As an example, the vertical height of each groove 12 is 3 mm-3.2 mm; the horizontal width of each groove 12 is 3 mm-3.2 mm. In this embodiment, the vertical height H of each groove 12 is 3.06 mm, and the horizontal width W of each groove 12 is 3.16 mm.

Specifically, edges 12a of the grooves 12 close to the inner sidewall 111 and the outer sidewall 112 are in an arc shape.

Referring to FIG. 3, in this embodiment, by arranging the edges 12a of the grooves 12 close to the inner sidewall 111 and outer sidewall 112 to be in an arc shape, the occurrence of particle pollutants caused by the wafer polishing locating ring 10 wearing the polishing pad 40 can be avoided, thus preventing scratch defects from appearing on the surface of the wafer 30, improving the product yield, and also prolonging the service life of the polishing pad 40.

As an example, the angle of the arc shape is 30°-75°.

Specifically, the grooves 12 are inclined clockwise from the inner sidewall 111 to the outer sidewall 112.

In this embodiment, the inclination direction of the grooves 12 is determined based on the rotation direction of the polishing head 50 and the polishing pad 40 to conform to the flow direction of the polishing fluid 20, so that the polishing fluid 20 flows into the wafer 30 through the groove 12.

Specifically, the material of the wafer polishing locating ring 10 includes polyphenylene sulfide, polyether ether ketone, or semi-crystalline thermoplastic polymer. Exemplarily, in this embodiment, the material of the wafer polishing locating ring 10 is polyphenylene sulfide (PPS).

Referring to FIG. 4, this embodiment further provides a chemical mechanical polishing device. The chemical mechanical polishing device includes a polishing disc 60, a polishing pad 40 adhered to the polishing disc 60, a polishing head 50, and the wafer polishing locating ring 10 according to any one of the embodiments. The wafer polishing locating ring 10 is provided on the polishing head 50.

In this embodiment, the wafer polishing locating ring 10 is located around the wafer 30 to accommodate the wafer 30 within the space defined by the ring body 11, preventing it from sliding out of the ring body 11, thus enabling the wafer 30 to be better fixed on the polishing head 50 and preventing it from being displaced.

Specifically, the chemical mechanical polishing device further includes a rubber diaphragm 70, and the rubber diaphragm 70 is provided on the polishing head 50.

In this embodiment, the rubber diaphragm 70 is placed within the space defined by the ring body 11 and above the wafer 30. By applying pressure to the rubber diaphragm 70 through the polishing head 50, the rubber diaphragm 70 is tightly attached to the wafer 30 to evenly distribute the pressure on the wafer 30.

To sum up, by adopting the wafer polishing locating ring and the chemical mechanical polishing device provided in this application, the service life of the wafer polishing locating ring is prolonged by setting the opening angle of the grooves in the ring body of the wafer polishing locating ring to an acute angle. Moreover, other consumables (such as rubber diaphragm) used in the polishing head and the wafer polishing locating ring need to be replaced simultaneously. Therefore, while the service life of the wafer polishing locating ring is prolonged, the use time of other consumables used in the polishing head can also be synchronously prolonged, thus reducing the cost and time of maintenance of the chemical mechanical polishing device. Therefore, this application effectively overcomes various disadvantages in the existing technology and has high industrial utilization value.

The above embodiments are only used for exemplarily describing the principle and efficacy of this application, instead of limiting this application. Those skilled in the art may modify or change the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed in this application should still be covered by the claims of this application.

Claims

1. A wafer polishing locating ring, comprising a ring body and a plurality of grooves formed in the ring body, wherein the ring body is a circular ring body and comprises an inner sidewall and an outer sidewall, the grooves run through the outer sidewall and inner sidewall of the ring body, and an included angle between a sidewall and a bottom of each groove is an acute angle.

2. The wafer polishing locating ring according to claim 1, wherein two sidewalls of each groove are in parallel.

3. The wafer polishing locating ring according to claim 1, wherein a vertical height of each groove is 3 mm-4 mm; and a horizontal width of each groove is 3 mm-4 mm.

4. The wafer polishing locating ring according to claim 3, wherein the vertical height of each groove is 3 mm-3.2 mm; and the horizontal width of each groove is 3 mm-3.2 mm.

5. The wafer polishing locating ring according to claim 1, wherein edges of the grooves close to the inner sidewall and the outer sidewall are in an arc shape.

6. The wafer polishing locating ring according to claim 5, wherein an angle of the arc shape is 30°-75°.

7. The wafer polishing locating ring according to claim 1, wherein the grooves are inclined clockwise from the inner sidewall to the outer sidewall.

8. The wafer polishing locating ring according to claim 1, wherein a material of the wafer polishing locating ring comprises polyphenylene sulfide, polyether ether ketone, or semi-crystalline thermoplastic polymer.

9. A chemical mechanical polishing device, comprising a polishing disc, a polishing pad adhered to the polishing disc, a polishing head, and the wafer polishing locating ring according to claim 1, wherein the wafer polishing locating ring is provided on the polishing head.

10. The chemical mechanical polishing device according to claim 9, wherein the chemical mechanical polishing device further comprises a rubber diaphragm, and the rubber diaphragm is provided on the polishing head.