Polishing pad, polishing method and method of forming polishing pad

Abstract

A polishing pad, a polishing method and a method of forming a polishing pad are provided. The polishing pad includes a polishing layer and a plurality of arc grooves. The arc grooves are disposed in the polishing layer. Each of the arc grooves has two ends, and at least one end thereof has an inclined wall. The angle between the inclined wall of each groove and the surface plane of the polishing layer is less than 90 degree.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No. 12/428,231, filed on Apr. 22, 2009, which claims the priority benefit of Taiwan application serial No. 97125981, filed on Jul. 9, 2008, the entireties of which are incorporated herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a polishing pad, a polishing method and a method of forming a polishing pad. More particularly, the polishing pad can provide a different slurry flow distribution.

2. Description of Related Art

With the progress of the industry, a planarization process is often adopted as a process for manufacturing various devices. A chemical mechanical polishing (CMP) process is often used in the planarization process in the industry. General speaking, the chemical mechanical polishing process supplies slurry having a chemical on the polishing pad, applies a pressure on the substrate to be polished to press it on the polishing pad, and provides a relative motion between the substrate and the polishing pad. Through the mechanical friction generated by the relative motion and the chemical effects of the slurry, a portion of the surface layer of the substrate is removed to make the surface flat and smooth so as to achieve planarization.

FIG. 1 is a schematic top view of a conventional polishing pad. FIG. 1A is a cross-section view of the polishing pad taken along a line A-A′ in FIG. 1. Referring to FIG. 1, a polishing pad 100 includes a polishing layer 102 and a plurality of circumferential grooves 104. The polishing layer 102 is in contact with a surface of a substrate 105 (e.g. a wafer). The plurality of circumferential grooves 104 is disposed in the polishing layer 102 in the manner of concentric circles. The circumferential grooves 104 are used to contain slurry. When the polishing process is performed, the polishing pad 100 moves in a rotational direction 101, for example, a counterclockwise direction as shown in FIG. 1. At the same time when the polishing pad 100 rotates, the slurry is continuously supplied to the polishing pad 100 and flows between the polishing layer 102 and the substrate 105.

As shown in FIG. 1A, part of the slurry flows to the surface of the polishing layer 102 through the centrifugal force generated from the rotation of the polishing pad 100, as shown in a flow direction 103. However, most of the slurry 108 is still contained in the circumferential grooves 104 and only a small portion thereof flows to the surface of the polishing layer 102. The distribution of the slurry has an effect on polishing characteristics during the polishing process.

Therefore, it is needed to provide a polishing pad which can provide a different slurry flow distribution for industry in response to the requirements of various polishing processes.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a polishing pad and a polishing method using the polishing pad. The polishing pad can provide a different slurry flow distribution.

The present invention further provides a forming method of a polishing pad, wherein the formed polishing pad provides a different slurry flow distribution.

The present invention provides a polishing pad and a polishing method using the polishing pad. The polishing pad includes a polishing layer and a plurality of arc grooves. The plurality of arc grooves are disposed in the polishing layer. Each of the plurality of arc grooves has two ends, and at least one end thereof has an inclined wall. The angle between the inclined wall and the surface plane of the polishing layer is less than 90 degrees.

The present invention further provides a polishing pad and a polishing method using the polishing pad. The polishing pad includes a polishing layer, a plurality of arc grooves, and a polishing surface. The plurality of arc grooves are disposed in the polishing layer and surrounding the rotational axis of the polishing pad. The polishing surface is disposed between the arc grooves and including a first polishing region and a second polishing region. The first polishing region is disposed between neighboring two arc grooves in the circumferential direction. The second polishing region is disposed between neighboring two arc grooves in the radial direction. The first polishing region becomes larger gradually as the polishing surface is abraded downward.

The present invention further provides a polishing pad and a polishing method using the polishing pad. The polishing pad includes a polishing layer and a plurality of arc grooves. The plurality of arc grooves are disposed in the polishing layer to form a plurality of fan-shaped regions, wherein the arc grooves in the same fan-shaped region are concentric arc grooves with unequal radii, and the center of the concentric arc grooves in at least one fan-shaped region does not overlap with the rotational axis of the polishing pad.

The present invention provides a method of forming a polishing pad. First, a polishing layer is provided. Thereafter, a plurality of concave regions is formed in the polishing layer. Afterwards, a plurality of arc grooves is formed in regions outside the concave regions.

The polishing pad of the present invention is a polishing pad which can provide a different slurry flow distribution.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, several embodiments accompanied with figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic top view of a conventional polishing pad.

FIG. 1A is a cross-section view of the polishing pad taken along a line A-A′ in FIG. 1.

FIG. 2A is a schematic top view of a polishing pad according to a first embodiment of the present invention.

FIG. 2B is a schematic top view of a polishing pad according to a second embodiment of the present invention.

FIG. 2C is a schematic top view of a polishing pad according to a third embodiment of the present invention.

FIG. 2D is a schematic top view of a polishing pad according to a fourth embodiment of the present invention.

FIG. 2E is a schematic top view of a polishing pad according to a fifth embodiment of the present invention.

FIG. 3 is a schematic top view of a polishing pad according to a sixth embodiment of the present invention.

FIG. 4 is a schematic top view of a method of forming the polishing pad according to the first embodiment of the present invention.

FIG. 5A is a cross-section view of the polishing pad structure taken along a line I-I′ in FIG. 4 according to a first method of the present invention.

FIG. 5B is a cross-section view of the polishing pad structure taken along a line I-I′ in FIG. 4 according to a second method of the present invention.

FIG. 6 is a schematic top view of a method of forming the polishing pad according to the second embodiment of the present invention.

FIG. 7 is a schematic top view of a method of forming the polishing pad according to the fifth embodiment of the present invention.

The Seventh Embodiment

FIG. 8 is a schematic top view of a polishing pad according to a seventh embodiment of the present invention. This embodiment is similar to the fifth embodiment depicted in FIG. 2E, but with the interposed regions 206a, 206b, 206c, and 206d including at least one of the bent line radial extending grooves 216a, 216b, 216c, and 216d.

The Eighth Embodiment

FIG. 9 is a schematic top view of a polishing pad according to an eighth embodiment of the present invention. This embodiment is similar to the fifth embodiment depicted in FIG. 2E, but with the interposed regions 206a, 206b, 206c, and 206d including at least one of the arc radial extending grooves 216a, 216b, 216c, and 216d.

The Ninth Embodiment

FIG. 10 is a schematic top view of a polishing pad according to a ninth embodiment of the present invention. This embodiment is similar to the fifth embodiment depicted in FIG. 2E, but with the interposed regions 206a, 206b, 206c, and 206d including at least one of the straight line radial extending grooves 216a, 216b, 216c, and 216d.

The Tenth Embodiment

FIG. 11 is a schematic top view of a polishing pad according to a tenth embodiment of the present invention. This embodiment is similar to the fifth embodiment depicted in FIG. 2E, but the arc grooves 208a, 210a, and 212a in the tenth embodiment are elliptical rather than circular.

The Eleventh Embodiment

FIG. 12 is a schematic top view of a polishing pad according to an eleventh embodiment of the present invention. This embodiment is similar to the fifth embodiment depicted in FIG. 2E, but the arc grooves 208a, 210a, and 212a in the eleventh embodiment are parabolic rather than circular.

The Twelfth Embodiment

FIG. 13 is a schematic top view of a polishing pad according to a twelfth embodiment of the present invention. This embodiment is similar to the fifth embodiment depicted in FIG. 2E, but the arc grooves 208a, 210a, and 212a in the twelfth embodiment are irregular rather than circular.

Although the present invention has been disclosed above by the embodiments, they are not intended to limit the present invention. Anybody skilled in the art can make some modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the protected range of the present invention falls in the appended claims.

Claims

1. A polishing pad, comprising:

a polishing layer; and

a plurality of arc grooves, disposed in the polishing layer and forming a plurality of fan-shaped regions,

wherein the plurality of arc grooves in the same fan-shaped region are concentric arc grooves with unequal radii, and

a radial center of the concentric arc grooves in at least one fan-shaped region does not overlap with a rotational axis of the polishing pad, wherein one or both of the following conditions is satisfied:

(a) the radial center of the concentric arc grooves in at least one fan-shaped region is located inside the polishing layer and spaced apart from an outer circumferential edge of the polishing layer, and

(b) each of the concentric arc grooves in the at least one fan-shaped region has two ends, at least one of the ends located inside the polishing layer and spaced apart from the outer circumferential edge of the polishing layer.

2. The polishing pad according to claim 1, wherein with respect to a relative motion of the polishing pad, each of the plurality of arc grooves has a front end and a back end, at least the back end thereof has an inclined wall, and an angle between the inclined wall and a surface plane of the polishing layer is less than 90 degrees.

3. The polishing pad according to claim 2, wherein the angle is between 5 and 60 degrees.

4. The polishing pad according to claim 1, wherein each of the concentric arc grooves in the fan-shaped region whose center does not overlap with the rotational axis of the polishing pad has a front end and a back end with respect to a relative motion of the polishing pad, and each of the concentric arc grooves in the fan-shaped region whose center dose not overlap with the rotational axis of the polishing pad has a distance to the rotational axis gradually becomes becoming shorter or longer from the front end to the back end.

5. The polishing pad according to claim 1, further comprising an interposed region between two neighboring fan-shaped regions.

6. The polishing pad according to claim 5, wherein the interposed region further comprises at least one radial extending groove.

7. The polishing pad according to claim 6, a shape of the radial extending groove is selected from the group consisting of a straight line, a bent line, an arc, and combinations thereof.

8. A method of forming a polishing pad, comprising:

providing a polishing layer;

forming a plurality of concave regions in the polishing layer; and

forming a plurality of arc grooves in regions outside the concave regions; and

recovering the concave regions to form a smooth surface in the polishing layer,

wherein each of the plurality of arc grooves has two ends, at least one end thereof has an inclined wall, and an angle between the inclined wall and a surface plane of the polishing layer is less than 90 degrees.

9. The method of forming the polishing pad according to claim 8, wherein the method of forming the plurality of concave regions and the plurality of arc grooves comprises:

providing a sucker device, wherein the sucker device comprises a plurality of recess regions corresponding to the plurality of concave regions; fixing the polishing pad using the sucker device to form the concave regions; and forming the plurality of arc grooves in the regions outside the concave regions.

10. The method of forming the polishing pad according to claim 8, wherein a method of forming the plurality of concave regions and the plurality of arc grooves comprises:

providing a sucker device and a gasket, wherein the gasket comprises a plurality of recess regions corresponding to the concave regions; fixing the polishing pad using the sucker device and the gasket to form the plurality of concave regions; and forming the plurality of arc grooves in the regions outside the plurality of concave regions.

11. The method of forming the polishing pad according to claim 8, wherein a method of forming the plurality of concave regions and the plurality of arc grooves comprises:

forming a plurality of recess regions corresponding to the plurality of concave regions in a back surface of the polishing pad; providing a sucker device to fix the polishing pad to form the plurality of concave regions; and forming the plurality of arc grooves in the regions outside the plurality of concave regions.

12. The method of forming the polishing pad according to claim 8, wherein a method of forming the plurality of concave regions comprises providing a vacuum sucker device or an electrostatic sucker device.

13. The method of forming the polishing pad according to claim 8, wherein a depth of the plurality of concave regions is greater than a depth of the plurality of arc grooves.

14. The method of forming the polishing pad according to claim 8, wherein the regions outside the plurality of concave regions are a plurality of fan-shaped regions and the plurality of concave regions are between two neighboring fan-shaped regions.

15. The method of forming the polishing pad according to claim 14, wherein the plurality of arc grooves in the same fan-shaped region are concentric arc grooves with unequal radii.

16. The method of forming the polishing pad according to claim 8, wherein the plurality of arc grooves comprise concentric arc grooves with unequal radii and concentric arc grooves with the same radius.

17. The method of forming the polishing pad according to claim 16, wherein the concentric arc grooves with the same radius have a total length between 55% and 95% of a projected circumference.

18. The method of forming the polishing pad according to claim 16, wherein the concentric arc grooves with the same radius have a total length between 15% and 45% of a projected circumference.

19. The method of forming the polishing pad according to claim 16, wherein the concentric arc grooves at even-numbered circles and the concentric arc grooves at odd-numbered circles are alternately arranged.

20. The method of forming the polishing pad according to claim 19, wherein the concentric arc grooves at the even-numbered circles and the concentric arc grooves at the odd-numbered circles are formed by a process of forming the plurality of concave regions and the plurality of arc grooves in two steps, and the polishing pad is rotated by an angle between the two steps.

21. The method of forming the polishing pad according to claim 15, wherein a center of the concentric arc grooves in one fan-shaped region does not overlap with a center of the concentric arc grooves in another fan-shaped region.

22. The method of forming the polishing pad according to claim 15, wherein the radii of the concentric arc grooves in a fan-shaped region are unequal to the radii of the concentric arc grooves in a neighboring fan-shaped region but are equal to the radii of the concentric arc grooves in a non-neighboring fan-shaped region.

23. A method of producing an industrial device comprising:

at least a step of polishing a substrate by using the a polishing pad according to claim 1, the polishing pad comprising:

a polishing layer; and

a plurality of arc grooves, disposed in the polishing layer and forming a plurality of fan-shaped regions,

wherein the plurality of arc grooves in the same fan-shaped region are concentric arc grooves with unequal radii, and

a radial center of the concentric arc grooves in at least one fan-shaped region does not overlap with a rotational axis of the polishing pad, wherein one or both of the following conditions is satisfied:

(a) the radial center of the concentric arc grooves in at least one fan-shaped region is located inside the polishing layer and spaced apart from an outer circumferential edge of the polishing layer, and

(b) each of the concentric arc grooves in the at least one fan-shaped region has two ends, at least one of the ends located inside the polishing layer and spaced apart from the outer circumferential edge of the polishing layer.

24. The polishing pad according to claim 1, wherein shapes of the plurality of arc grooves are selected from the group consisting of circular arcs, elliptical arcs, parabolic arcs, irregular arcs, and combinations thereof.