TWI409137B - Polishing pad and the method of forming micro-structure thereof - Google Patents

Abstract

This invention is related to a polishing pad, and more particularly a polishing pad with flexible micro-structure. The polishing pad comprises a connecting surface and a polishing surface. The connecting surface is used to secure on a polishing device. The polishing surface with flexible micro-structure is used to grind and adequately press close to the surface of semiconductor piece. The present invention not only increases the area of polishing surface that contact with the semiconductor piece but also get over the difficulty in pressing close to different piece. It will save grinding time and have a better effect.

Description

Polishing pad and micro structure forming method thereof

The present invention relates to a polishing pad, and more particularly to a polishing pad having an elastic microstructure.

Most electronic wafers are formed by layering different materials. For example, a semiconductor wafer is one of the stratified materials. When each new material layer is added, it is often necessary to grind or smash. The grinding step removes excess layer material to planarize the wafer or achieve other purposes, and such grinding is often referred to as Chemical Mechanical Polishing (CMP). Since the wafer is formed from a variety of different thin material layers, multiple CMP grinding steps must be performed to evenly remove the material layer from the surface of the wafer.

In a typical CMP, a wafer is flip-chip mounted on a CMP carrier, the carrier can drive the wafer to rotate, and the polishing pad is mounted on another carrier, and the carrier also drives the polishing pad to rotate, usually in polishing. In the process, a chemical slurry is introduced between the wafer and the polishing pad, so that the wafer layer portion may chemically dissolve with the chemical polishing liquid or physically interact with the particles in the chemical polishing liquid. Remove some of the wafer layers. However, if such a grinding method encounters a workpiece to be ground with an uneven surface, but a uniform flattening of the surface of the workpiece to be ground is required, the surface area of the polishing pad in contact with the workpiece to be ground is usually limited to a point, and is to be ground to a certain extent. At the same time, the surface area of the contact will gradually increase, so that not only the required grinding time will be increased, but also the polishing pad is likely to be unevenly used and the polishing pad cannot be used for a long time. Moreover, if a workpiece to be ground which is uneven on the surface is encountered during grinding, but it is required to perform uniform grinding according to the irregular undulation of the workpiece to be ground, the existing polishing pad cannot be applied to the surface of the workpiece to be ground, so The special needs of such grinding cannot be achieved.

In view of the above, the present invention provides a polishing pad having an elastic microstructure, wherein the microstructure can be fully adhered to the surface of the workpiece to be ground to increase the surface area of the contact during grinding, thereby saving time required for grinding. And can also overcome the grinding requirements of different objects to be ground, in addition to the micro-structure in addition to research When grinding, the particles on the surface of the object to be ground are removed to avoid scratching the surface of the object to be ground, and the microstructure has better water absorption capacity, so that more polishing liquid can be adsorbed during grinding to achieve better grinding effect, which is directed to the prior art. Improve it.

To solve the problems of the prior art, the present invention provides a polishing pad having an elastic microstructure. The polishing pad comprises a joint surface and a grinding surface, the joint surface is for fixing to a grinding device, and the grinding surface is used for grinding a semiconductor or other workpiece, wherein the grinding surface has an elastic micro structure, thereby making the grinding surface It is fully adhered to the surface of semiconductors or other workpieces to increase the surface area of the grinding surface in contact with semiconductors or other workpieces. It not only saves the time required for grinding, but also overcomes the grinding requirements of different objects to be ground to achieve better grinding. effect.

Accordingly, it is a primary object of the present invention to provide a polishing pad having a microstructure such that the abrasive surface can be sufficiently adhered to a surface of a semiconductor or other workpiece to achieve a better polishing effect.

Another object of the present invention is to provide a polishing pad having a microstructure that increases the surface area of the abrasive surface in contact with a semiconductor or other workpiece to achieve a better polishing effect.

It is still another object of the present invention to provide a polishing pad having a microstructure that saves time required for polishing and achieves a better polishing effect.

Another object of the present invention is to provide a polishing pad having a micro structure that can overcome the grinding requirements of different objects to be ground and achieve a better grinding effect.

It is still another object of the present invention to provide a polishing pad which can remove particles remaining in a semiconductor or other workpiece to prevent scratching of the surface of the semiconductor or other workpiece during polishing.

Another object of the present invention is to provide a polishing pad which has a better water absorption capacity, so that more polishing liquid can be adsorbed during polishing to achieve a better polishing effect.

Since the present invention discloses a polishing pad having a micro structure, the detailed manufacturing or processing process of some of the polishing pads utilized is achieved by the prior art, and therefore, in the following description, Full description. Moreover, the drawings in the following texts are not completely drawn in accordance with actual relevant dimensions, and their function is only to show a schematic diagram relating to the features of the present invention.

The first A is a schematic view of a preferred embodiment of the polishing pad of the present invention. The polishing pad 10 includes a bonding surface 11 and a grinding surface 12, and the bonding surface 11 is used for bonding and fixing the adhesive 13 (pressure sensitive adhesive) to a polishing device. 14 and the grinding surface 12 is used to grind a semiconductor or other workpiece 30, wherein the grinding surface 12 has an elastic microstructure 15 whereby the grinding surface 12 can be sufficiently adhered to the surface of the semiconductor or other workpiece 30, such as the first As shown in Fig. B, therefore, when the grinding surface 12 of the elastic microstructure 15 is in contact with the convex surface of the workpiece 30, the surface area of the elastic microstructure 15 in contact with the convex surface is increased (density) and provides a relatively dense pressure. Strength, when the grinding surface 12 of the elastic microstructure 15 is in contact with the concave surface of the workpiece 30, the surface area of the elastic microstructure 15 in contact with the concave surface is reduced (sparse), and the applied pressure is relatively loose, so the workpiece The grinding surface of 30 will have different force-receiving modes due to the influence of the elastic micro-structure 15, so that not only the time required for grinding can be saved, but also the grinding requirements of different objects to be ground can be overcome, and a better grinding effect can be achieved. .

2A and 2B are schematic views of a preferred embodiment of the microstructure of the polishing pad of the present invention, wherein the microstructure is a micro-groove 21 having a groove width of about 1 nm to 100 μm.

3A and 3B are schematic views of another preferred embodiment of the microstructure of the polishing pad of the present invention, wherein the microstructure is formed by the micro-foaming 22 technology, and the micro-foaming 14 technology can be physical Foaming technology or chemical foaming technology.

4A and 4B are schematic views of still another preferred embodiment of the microstructure of the polishing pad of the present invention, wherein the microstructure may be a hairpin-like microstructure 23 having a microstructure of about 1 nm to 100 μm. Since the hairiness structure has better water absorption capacity, more polishing liquid can be adsorbed during grinding to achieve a better grinding effect.

The present invention provides a preferred embodiment of a method for fabricating a microstructure of a polishing pad, wherein the microstructure is fabricated by a micro-foaming technique, and the method of making the polishing pad comprises the steps of: providing a resin and a plurality of nanoparticles Grade particles, stirred nano-sized particles and resin, so that the nano-sized particles are uniformly suspended in the resin, the resin is cured to form a sheet, and the nano-sized particles are removed to make the surface of the sheet There are a plurality of slots to form a microstructure, wherein the method of curing the resin or removing the nano-sized particles may be a heating method.

The present invention provides another preferred embodiment of a method for fabricating a microstructure of a polishing pad, wherein the microstructure is fabricated by a micro-foaming technique, and the method of making the polishing pad comprises the steps of: providing a resin and a plurality of salts The particles are mixed in the resin, and the salt particles and the resin are stirred, so that the salt particles are uniformly suspended and distributed in the resin, the resin is solidified to form a sheet, and the salt particles are removed, so that the surface of the sheet has a plurality of slots to form a microstructure. Wherein the resin may be cured by heating, and the salt particles may be removed using an aqueous solution.

The present invention provides a further preferred embodiment of a method for fabricating a microstructure of a polishing pad, wherein the microstructure is fabricated by a microfoaming technique, and the method of making the polishing pad comprises the steps of: providing a resin and a solvent to the resin The solvent and the resin are immiscible, and the solvent may be dimethylformamide (DMF) or other hydrophilic solvent, and the mixture of the resin and the solvent is stirred, so that the solvent is uniformly distributed in the resin, and the resin is cured to form a The sheet is removed, so that the surface of the sheet has a plurality of slits to form a microstructure, wherein the resin can be cured by heating, and the solvent can be removed with an aqueous solution.

The present invention provides a further preferred embodiment of a method for fabricating a micro-structure of a polishing pad. The method for fabricating a polishing pad comprises the steps of: providing a substrate formed of ultrafine fibers, impregnating the substrate in a resin, and curing the substrate. The substrate after impregnating the resin is formed into a sheet, and the surface of the sheet is ground to obtain a hairy micro-structure in which the resin can be cured by heating.

The present invention provides a further preferred embodiment of a method for fabricating a microstructure of a polishing pad, wherein the microstructure is fabricated by a micro-foaming technique, and the method of making the polishing pad comprises the steps of: providing a resin and a foaming agent In the resin, the resin and the blowing agent mixture are stirred, so that the foaming agent is uniformly distributed in the resin, the resin is cured to form a sheet, and the resin is heated to vaporize the foaming agent, thereby causing the surface of the sheet to have A plurality of slots are formed to form the microstructure, wherein the step of curing the resin can be performed in conjunction with the step of heating the resin.

The invention provides an abrasive pad with an elastic microstructure, wherein the microstructure can be fully adhered to the surface of the workpiece to be ground to increase the surface area of the contact during grinding, which not only saves the time required for grinding In addition, it can also overcome the grinding requirements of different objects to be ground. In addition, the micro structure can remove the particles on the surface of the object to be ground during grinding, avoiding scratches on the surface of the object to be ground, and the micro structure has better water absorption capacity. A large amount of polishing liquid is adsorbed during polishing to achieve a better polishing effect.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the patent application rights of the present invention. The above description should be understood and implemented by those skilled in the art, so that the other embodiments are not deviated from the present invention. Equivalent changes or modifications made in the spirit of the disclosure are intended to be included in the scope of the claims below.

10‧‧‧ polishing pad

11‧‧‧ joint surface

12‧‧‧ Grinding

13‧‧‧Viscos

14‧‧‧ grinding device

15‧‧‧Microstructure

21‧‧‧ miniature grooves

22‧‧‧Microfoam

221‧‧‧ slots

23‧‧‧Mao-like microstructure

Figure A is a schematic view of a polishing apparatus.

Figure B is a cross-sectional view of an elastic microstructure of a polishing pad.

Figure 2A is a schematic view of a micro-groove of a polishing pad.

Figure B is a cross-sectional view of a micro-groove of a polishing pad.

The third A is a schematic view of the micro-foaming of a polishing pad.

Figure 3B is a cross-sectional view of a microfoam of a polishing pad.

Figure 4A is a schematic view of a hairy micro-structure of a polishing pad.

Figure 4B is a cross-sectional view of a hairy micro-structure of a polishing pad.

10‧‧‧ polishing pad

11‧‧‧ joint surface

12‧‧‧ Grinding

13‧‧‧Viscos

14‧‧‧ grinding device

15‧‧‧Microstructure

Claims (4)

A method of forming a microstructure on a polishing pad, comprising the steps of: providing a substrate formed of an ultrafine fiber; providing a resin, immersing the substrate of the ultrafine fiber in the resin; curing the impregnated portion Substrate to form a sheet; and grinding a surface of the sheet to provide a microstructure on the surface. A method of forming a microstructure on a polishing pad as described in claim 1 wherein the microstructure is a micro-groove. A method of forming a microstructure on a polishing pad as described in claim 1 wherein the microstructure is a hairy micro-structure. A method of forming a microstructure on a polishing pad as described in claim 3, wherein the hairpin-like microstructure has a size of about 1 nm to 100 μm.