JP2000296461A - Backing pad structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate separating work by a transfer device by preventing any adhesion of templates to abrasive cloth. SOLUTION: A backing pad structure 1 comprises a backing pad 2 and a template 3 fixed to the backing pad 2 via an adhesive 5. The template 3 has a water-repellent surface or a surface roughness Ra of 0.5 μm or more. With a semiconductor wafer 20 positioned in a semiconductor wafer holding hole in the template 3, relative movement of the backing pad structure 1 and a surface plate 15, when polishing fluid 21 is,supplied between the semiconductor wafer 20 and abrasive cloth 16, causes the abrasive cloth 16 to polish the polishing surface of the semiconductor wafer 20 and the surface of the template 3, which never adheres to the abrasive cloth 16 after the polishing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing pad structure, and more particularly to a backing pad structure capable of preventing a polishing apparatus from sticking to a polishing cloth.

[0002]

2. Description of the Related Art One of the methods for polishing semiconductor wafers is a waterless waxless polishing method, and a polishing apparatus 10 as shown in FIGS. 4 and 5 is used in this polishing method.

That is, the polishing apparatus 10 includes a pressing member 11 composed of a pressure plate 12 and a sticking plate 13, a backing pad structure 31 attached to the pressing member 11 via an adhesive 5 (or an adhesive), A surface plate 15 provided below and opposed to the backing pad structure 31, and an adhesive 5 (or an adhesive) on the upper surface of the surface plate 15.
And a polishing cloth 16 attached through the nip.

In this case, the backing pad structure 31
Is a hydrophobic backing pad 32 made of foamed polyurethane or the like, which is attached to the attachment plate 13 of the pressing member 11 via an adhesive 5 (or an adhesive).
And a template 33 that is attached to the backing pad 32 via an adhesive 5 (or an adhesive) and that is formed of an epoxy glass resin or the like having holes 34 for holding a semiconductor wafer at at least one location.

[0005] The nap layer 32 a of the backing pad 32 of the backing pad structure 31 is filled with a suitable amount of water to form a hole 3 for holding a semiconductor wafer of the template 33.
4, a semiconductor wafer 20 is positioned in this state, and in this state, a load is applied by the pressing member 11 so that the backing pad structure 3
1 is pressed in the direction of the surface plate 15 and the polishing surface 20a of the semiconductor wafer 20 is pressed against the polishing cloth 16 on the surface plate 15. When water is pushed out from the groove of the nap layer 32a of the backing pad 32, water is pushed out. Becomes negative pressure, and the semiconductor wafer 20 is attracted to the backing pad 32 by this negative pressure.

In this state, the polishing plate 21 containing the soft abrasive grains is supplied between the polishing surface 20 a of the semiconductor wafer 20 and the polishing pad 16, and the adhesive plate 13 and the platen 15 are supplied.
Are relatively polished, whereby the polished surface 20a of the semiconductor wafer 20 is polished to a predetermined surface roughness.

However, when the semiconductor wafer 20 is polished while holding the semiconductor wafer 20 on the backing pad structure 31 having the above-described structure, the polishing proceeds and the semiconductor wafer 20 is polished.
When the polishing surface 20a becomes a mirror surface, since the polishing cloth 16 has a hydrophobic structure like the backing pad 32, an attraction force also acts between the polishing surface 20a of the semiconductor wafer 20 and the polishing cloth 16, The polished surface 20a of the semiconductor wafer 20 adheres to the polishing pad 16 due to the attraction force.

Further, the surface 33a of the template 33
(The surface facing the polishing cloth 16) is also polished by contacting the polishing cloth 16 during polishing of the semiconductor wafer 20, so that an attraction force acts between the surface 33 a of the template 33 and the polishing cloth 16. The surface 33 of the template 33 by the suction force
a also adheres to the polishing pad 16.

Thus, the polished surface 2 of the semiconductor wafer 20
When the surface 0a and the surface 33a of the template 33 are adsorbed to the polishing pad 16, the entire adhering plate 13 is brought into a state as if adsorbed to the polishing pad 16, and after the polishing is completed, the adhering plate 13 is moved by a transfer machine (not shown). When peeling 13 from the polishing apparatus 10, a large force is required,
Problems such as difficulty in peeling will occur.

The present invention solves the above-described problems of the conventional device. When a semiconductor wafer is polished, the surface of the template (the surface facing the polishing cloth) adheres to the polishing cloth. Accordingly, it is an object of the present invention to provide a backing pad structure that can be easily peeled off from a polishing apparatus without requiring a large force by a transfer machine after polishing is completed.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a backing pad structure attached to a pressing member of a polishing apparatus, wherein the pressing member is provided with an adhesive or an adhesive. A backing pad having hydrophobicity, which is attached to the backing pad via a pressure-sensitive adhesive or an adhesive, and a template provided with a hole for holding a semiconductor wafer at at least one location penetrating therethrough, The present invention employs means for forming the surface of the polishing apparatus of the template so that the surface of the polishing apparatus is not easily adhered when the template comes into contact with the polishing cloth. Then, the surface of the template is coated with a coating agent, and the surface is formed to have a surface roughness through which air can flow when the template comes into contact with the polishing cloth, thereby forming the surface less sticky or forming the template. In this method, the surface is subjected to a water-repellent treatment, and the surface is formed so that the surface is hardly adhered when the template comes in contact with the polishing cloth.

[0012]

According to the present invention, by employing the above-described means, even if the surface of the template comes into contact with the polishing cloth during polishing of the semiconductor wafer, the template and the polishing cloth are formed so as not to stick to each other. After the polishing, the template is not attached to the polishing cloth.

[0013]

Embodiments of the present invention shown in the drawings will be described below. FIGS. 1 to 3 show an embodiment of a backing pad structure according to the present invention.
A backing pad 2 made of foamed polyurethane or the like, which is attached to an attachment plate 13 attached to the pressure plate 12 of the pressing member 11 via an adhesive 5 (or an adhesive); And a template 3 made of an epoxy glass resin or the like, which is attached via an agent 5 (or an adhesive) and is provided in at least one place with a hole 4 for holding a semiconductor wafer penetrating therethrough.

In this case, the surface 3a of the template 3 {the surface facing the polishing cloth 16 attached to the surface plate 15 of the polishing apparatus 10 via the adhesive 5 (or an adhesive)} has a rough surface roughness by grinding. (Ra: 0.5 μm or more, preferably 0.8 to 20 μm). That is, the surface 3 a of the template 3 is formed to have a surface roughness that allows air to flow through between the template 3 and the polishing cloth 16 even if the surface 3 a contacts the polishing cloth 16 during polishing.

Then, the nap layer 2a of the backing pad 2 of the backing pad structure 1 constructed as described above is made to contain a suitable amount of water, and the semiconductor wafer 20 is positioned in the hole 4 for holding the semiconductor wafer of the template 3. In this state, a load is applied by the pressing member 11 of the polishing apparatus 10 to press the backing pad structure 1 in the direction of the surface plate 15, and the polishing surface 20 a of the semiconductor wafer 20 is pressed against the polishing cloth 16 on the surface plate 15. Nap layer 2 of backing pad 2
The water is extruded from the inside of the groove a, and the inside of the groove becomes a negative pressure.
Will be adsorbed.

In this state, the backing pad structure 1 and the platen 15 are moved relative to each other while a polishing liquid 21 containing soft abrasive grains is supplied between the polishing surface 20a of the semiconductor wafer 20 and the polishing pad 16 in this state. The semiconductor wafer 2
The 0 polished surface 20a is polished to a predetermined surface roughness.

In this case, when the polishing proceeds and the polishing surface 20a of the semiconductor wafer 20 approaches the mirror surface, the polishing cloth 16 has the same structure as the backing pad 2, so that the polishing surface 20a of the semiconductor wafer 20 and the polishing cloth 16 A suction force acts between the polished surfaces 2 of the semiconductor wafer 20 due to the suction force.
0a is adsorbed on the polishing pad 16.

However, the surface 3a of the template 3 is also polished in contact with the polishing pad 16 due to the elastic change of the polishing pad 16 and the backing pad 2, but the surface 3a of the template 3 has a rough surface (Ra). : 0.5 μm or more, preferably 0.8 to 20 μm), so that air flows between the template 3 and the polishing cloth 16 during polishing, and the surface 3a of the template 3 during polishing. An attraction force acts between the polishing pad 16 and the polishing pad 16, and the attraction force does not cause the surface 3 a of the template 3 to be attracted to the polishing pad 16.

Accordingly, when the backing pad structure 1 is peeled from the polishing apparatus 10 by a transfer machine (not shown) after the polishing of the polishing surface 20a of the semiconductor wafer 20, the polishing surface 20a of the semiconductor wafer 20 and the template 3 are removed. The surface 3a is not attracted to the polishing cloth 16 and the peeling is not difficult, and the peeling can be easily performed with a small force.

In the above description, the surface roughness of the surface 3a of the template 3 is increased by grinding (Ra:
0.5 μm or more, preferably 0.8 to 20 μm), but the surface 3a of the template 3 may be coated with ceramics to form a rough surface.
The surface roughness may be formed by a molding method such as pressing. The surface 3a of the template 3 can be prevented from being attached to the polishing pad 16 by increasing the wettability without forming the surface 3a of the template 3 coarsely by grinding or coating with a coating agent. Further, even if the surface 3a of the template 3 is formed to be water-repellent, the adhesion can be prevented.

[0021]

The present invention is constructed as described above, and the surface of the template (the surface facing the polishing cloth of the polishing apparatus) is formed to be rough or water-repellent to form the template. By being formed so that it does not stick easily when it comes in contact with the polishing cloth, even if the surface of the template comes into contact with the polishing cloth when polishing the polished surface of the semiconductor wafer, the adhesive force between the template and the polishing cloth There is nothing like working. Therefore, when peeling from the polishing apparatus by the transfer device after the polishing is completed, the peeling does not become difficult and an excellent effect that the peeling can be easily performed is achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a backing pad structure according to the present invention, and is a perspective view taken along line AA of FIG.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is an enlarged view of a portion C in FIG. 2;

FIG. 4 is a sectional view showing an example of a conventional backing pad structure.

FIG. 5 is an enlarged view of a portion D in FIG. 4;

[Explanation of symbols]

 1, 31 Backing pad structure 2, 32 Backing pad 2a, 32a Nap layer 3, 33 Template 3a, 33a Surface 4, 34 ... Hole for holding semiconductor wafer 5 ... Adhesion Agent 10 Polishing device 11 Pressing member 12 Pressure plate 13 Adhering plate 15 Platen 16 Polishing cloth 20 Semiconductor wafer 20a Polishing surface 21 Polishing liquid

Claims (3)

[Claims] 1. A backing pad structure attached to a pressing member of a polishing apparatus, comprising: a backing pad having hydrophobicity attached to the pressing member via an adhesive or an adhesive; and an adhesive or a backing pad attached to the backing pad. A template provided in a state in which a hole for holding a semiconductor wafer is penetrated in at least one place, and a surface of a polishing device for the template, when the template comes into contact with a polishing cloth, A backing pad structure which is formed so as not to stick easily. 2. The method according to claim 1, wherein the surface of the template is coated with a coating agent, and the surface is formed to have a surface roughness through which air can flow when the template comes into contact with the polishing pad, thereby making the surface less sticky. 2. The backing pad structure according to 1. 3. The backing pad structure according to claim 1, wherein the surface of the template is subjected to a water-repellent treatment so that the surface is formed so as not to stick when the template comes in contact with the polishing cloth.