Polishing Pad

Abstract

The present invention provides a polishing pad, and is more particularly related to a polishing pad, the width of groove bottom of polishing surface of which is 0 mm. The polishing pad includes a polishing surface on which comprises a plurality of grooves, wherein each groove includes a groove opening and a groove bottom, the characteristic of which being that the width of groove bottom of polishing surface is 0 mm. Therefore, when the polishing step is performed, it is not easy for polishing particles suspended in the slurry to deposit on the groove bottom and the deposits can be prevented from scratching the concerned work piece to avoid damage of work piece.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a polishing pad, and more particularly, to a polishing pad, the width of groove bottom of polishing surface of which is 0 mm.

2. Description of the Prior Art

Electrical chips are formed by deposition of various laminate materials, for example, a silicon wafer is one of the substrates of laminate materials. Whenever a new laminate is deposited, a polishing or scratching step is often needed for removing excessive laminate materials to planarize the chip or to achieve other purposes. Such process of polishing is generally called chemical mechanical polishing (CMP). Since chips are formed by deposition of different thin film laminates, the CMP step needs to be performed for multiple times for evenly removing excessive laminate materials from the surface of a chip to achieve the purpose of planarization.

And usually when the CMP step is performed, chemical slurry is led in between the chip and the polishing pad for generating chemical reaction between the deposited thin film laminates and the chemical slurry or for generating mechanical reaction between the deposited thin film laminates and the particles in the chemical slurry to remove part of excessive thin film laminates on the surface of chip. However, the slurry existing between the polishing pad and the chip makes it easy for the polishing pad and the chip to become fully attached to each other, which thus causes disappearance of the force of friction between the polishing pad and the chip. Therefore, in order to achieve better polishing effect with the CMP step, the most common practice at present is to install groove on the surface of the polishing pad not only for increasing force of friction between the polishing pad and the chip but also for ensuring that the slurry is evenly distributed on the surface of the polishing pad and for letting polishing particles suspended in the slurry and the scraps to flow out through the groove.

However, in the common practice, when groove is installed on the surface of the polishing pad, there will be near-90-degree right-angle indentations on the bottom of the groove, as shown in FIG. 1. Therefore when the CMP step is performed, it is easy for the polishing particles in the slurry or the scraps produced by the polishing process to deposit in the corners of indentations without flowing out. The residual polishing particles or deposits will form larger particles and lead to scratching or damaging of surface of the polished object.

SUMMARY OF THE INVENTION

In order to solve the problems as described above, one objective of the present invention is to provide a polishing pad, the width of groove bottom of polishing surface of which is 0 mm to prevent the concerned work piece from being scratched and thus damaged by larger particles formed by polishing particles suspended in the slurry or scraps produced after polishing depositing on the bottom of groove.

Another objective of the present invention is to provide a polishing pad, the design of bottom of groove of polishing surface of which facilitates the flow of the slurry.

Still another objective of the present invention is to provide a polishing pad, the groove of which ensures that the slurry is evenly distributed on the polishing surface.

According to the above objectives, the present invention provides a polishing pad, the width of bottom of groove of polishing surface of which is 0 mm. The polishing pad includes a polishing surface on which comprises a plurality of grooves, wherein each groove includes a groove opening and a groove bottom, the characteristic of which being that the width of groove bottom of polishing surface is 0 mm. Therefore, when the polishing step is performed, it is not easy for polishing particles suspended in the slurry to deposit on the groove bottom and the deposits can be prevented from scratching the concerned work piece to avoid damage of work piece.

Therefore, with the design of width of groove bottom being 0 mm of the polishing pad provided by the present invention, not only can the deposition of polishing particles or scraps produced after polishing on the bottom of groove that may lead to scratching and damaging of work piece be prevented, but the flow of slurry can also be facilitated since the design of groove bottom prevents too much slurry from accumulating in the groove and thus achieves better polishing effect.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention as well as a preferred mode of use, further objectives and advantages thereof will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view of a polishing pad (prior art);

FIG. 2 is a front view of a polishing pad;

FIG. 3A is a sectional view of groove of a polishing pad;

FIG. 3B is a sectional view of groove of a polishing pad;

FIG. 3C is a sectional view of groove of a polishing pad; and

FIG. 3D is a sectional view of groove of a polishing pad.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention discloses a polishing pad, and more particularly, a polishing pad with the width of groove bottom of polishing surface of which being 0 mm. In the present invention, some details for manufacturing or processing polishing pad are achieved by applying conventional art, and therefore are not completely depicted in below description. And the drawings referred to in the following are not made according to the actual related sizes, the function of which is only to express and illustrate characteristics of the present invention.

FIG. 2 is a view of a preferred embodiment of polishing pad of the present invention. The polishing pad 20 includes a polishing surface 21 and a plurality of grooves 22 are disposed on the polishing surface 21, wherein each groove 22 includes a groove opening 221 and a groove bottom 222, as shown in FIG. 3A taken along section line a-a′ in FIG. 2, the characteristic of which being that the width of groove bottom 222 of polishing surface 21 is 0 mm.

FIG. 3A is a view of a preferred embodiment of groove of polishing pad according to the present invention. Between the groove opening 221 and the groove bottom 222 of the polishing pad 20 comprises at least one section 223, and the width of groove opening 221 and the width of groove bottom 222 are different, wherein between each section 223 comprises a bend to form an included angle. Thus part of section 223 can be a plane surface perpendicular to the groove bottom 222, and part of section 223 can be an inclined plane that is not perpendicular to the groove bottom 222.

FIG. 3B is a view of another preferred embodiment of groove of polishing pad according to the present invention. Between the groove opening 221 and the groove bottom 222 of the polishing pad 20 comprises at least one section 223, and the width of groove opening 221 and the width of groove bottom 222 are different, wherein the section 223 is V-shaped and is thus an inclined plane that is not perpendicular to the groove bottom 222.

FIG. 3C is a view of still another preferred embodiment of groove of polishing pad according to the present invention. Between the groove opening 221 and the groove bottom 222 of the polishing pad 20 comprises at least one section 223, and the width of groove opening and the width of groove bottom are different, wherein between the polishing surface 21 and the section 223 comprises a bent to form an included angle A1, degree of angle A1 being between 90 to 120 degrees.

FIG. 3D is a view of yet another preferred embodiment of groove of polishing pad according to the present invention. Between the groove opening 221 and the groove bottom 222 of the polishing pad 20 comprises at least one section 223, and the width of groove opening and the width of groove bottom are different, wherein the section 223 is U-shaped and the curved groove bottom thus facilitates the flow of slurry.

The present invention further provides still another preferred embodiment of groove of a polishing pad. Between the groove opening and the groove bottom of the polishing pad comprises at least one section, and the width of groove opening 221 and the width of groove bottom 222 are different, wherein the section is an irregular curved surface.

The aforementioned polishing pad can further include a connecting surface for being connected to a polishing surface of another polishing pad to form a two-layer polishing pad.

With the design of width of groove bottom of the polishing pad provided by the present invention being 0 mm, not only can the polishing particles or scraps produced after polishing be prevented from depositing on the groove bottom and thus leading to scrap and damage of work piece by the deposits, but the design of groove bottom also facilitates the flow of slurry so that excessive amount of slurry will not accumulate in the groove and better polishing effect can be achieved.

What are described above are only preferred embodiments of the present invention and are not for limiting the scope of the present invention; and the above description can be understood and put into practice by those who are skilled in the art. Therefore any equivalent modifications and arrangements made without departing from the spirit disclosed by the present invention should be encompassed by the appended claims accorded with the broadest interpretation.

Claims

1. A polishing pad, said polishing pad including a polishing surface, said polishing surface comprising a plurality of grooves on it, wherein said each groove includes a groove opening and a groove bottom, the characteristic of said polishing pad being in that width of said groove bottom of said polishing surface is 0 mm.

2. The polishing pad according to claim 1, wherein between said groove opening and said groove bottom of said polishing pad comprises at least one section.

3. The polishing pad according to claim 2, wherein said section is V-shaped.

4. The polishing pad according to claim 2, wherein said section is U-shaped.

5. The polishing pad according to claim 2, wherein between each said section comprises a bend to form an included angle.

6. The polishing pad according to claim 2, wherein between said polishing surface and said section comprises a bend to form an included angle.

7. The polishing pad according to claim 6, wherein degree of said included angle is about 90˜120 degrees.

8. The polishing pad according to claim 2, wherein said section is a plane surface perpendicular to said groove bottom.

9. The polishing pad according to claim 2, wherein said section is an inclined plane not perpendicular to said groove bottom.

10. The polishing pad according to claim 2, wherein said section is an irregular curved surface.

11. The polishing pad according to claim 1, wherein width of said groove opening and width of said groove bottom of said polishing pad are different.

12. The polishing pad according to claim 1, wherein said polishing pad further includes a connecting surface for being connected to polishing surface of another polishing pad.