JPS6248023A - Clothless polishing method of semiconductor wafer - Google Patents

Abstract

PURPOSE:To exclude a cloth from a polishing device by using both upper and lower plates by ultrafine particle abrasive plate, and by highly foamable liquid for frequently generating gas such as carbon dioxide gas or low viscosity liquid as a polisher. CONSTITUTION:A work 5 is attracted by vacuum to the lower surface 2 of the upper plate 1 of a one-side polishing unit, or secured by other method, pressed on the upper surface 4 of a lower plate 3 to be polished. The plate 3 of the unit is formed of any of an ultrafine abrasive plate, a resin plate, a metal and alumina plate containing resin as medium, a soft metal plate, a soft ceramic, an oil grease plate of pitch, tar or oil, and the polisher uses highly foamable liquid for frequently generating gas such as carbon dioxide gas or low viscosity liquid for polishing.

Description

[Detailed description of the invention] (Scope of industrial usegfI) The present invention is applicable to workpieces such as semiconductor wafers, silicon, GGG, etc.
The present invention relates to a method of polishing a workpiece.

(Structure and problems of conventional example) In order to polish the workpiece by pressing it between the lower surface of the upper plate and the upper surface of the lower plate, the conventional polishing device has a width of about 1 m to 1.51 mm on the processing surface of each plate. In order to adhere or form thick, flexible materials such as cloth, batts, urethane films, etc. by gluing or other methods, the edges of the workpiece, known as surface sagging and edge sagging, are polished. Because of this, the corners become rounded and the effective surface area decreases, so a dummy of the same height was used around the workpiece for polishing.

In addition, the high frictional resistance between the cloth and the workpiece generates heat, causing the workpiece to reach a high temperature and cause distortion, so cooling is required. This cannot be achieved without providing internal equipment for
In addition, the cloth deteriorates over time, necessitating replacement, and has many other problems.

(Object of the Invention) An object of the present invention is to solve each of the problems in view of the above-mentioned problems, and to provide an innovative polishing method that eliminates cloth from a polishing device.

(Structure of the Invention) This polishing device eliminates the cloth used in polishing devices for semiconductor wafers, and performs polishing by pressing the workpiece 5 between the lower surface 2 of the upper plate 1 and the upper surface 4 of the lower plate 3. Upper plate 1 or lower plate 2 of the polishing device and both upper and lower plates 1.2
Using one of the following plates: an ultrafine grinding wheel plate, a resin plate, a metal and alumina plate using resin as a medium, a soft metal plate, a soft ceramic, a pitch, tar, oil plate, etc., and carbon dioxide gas as an abrasive. This is a configuration in which crossless polishing is performed using a highly foaming liquid material that generates a large amount of gas, or a low viscosity liquid material.

(Explanation of Examples) The present invention will be explained below based on the drawings.

The drawings are of a single-sided polishing apparatus, with FIG. 1 being a side view of a conventional example, and FIG. 2 being a side view of an embodiment of the present invention.

This polishing device eliminates the cloth used in polishing devices for semiconductor wafers, and the workpiece 5 is fixed to the lower surface 2 of the upper plate 1 of the single-sided polishing device by vacuum suction or other methods, and the upper surface of the lower plate 3 is fixed. The lower plate 3 of the polishing device is pressed between the lower plate 3 of the polishing device and the lower plate 3 of the polishing device, which is pressed between the lower plate 3 of the polishing device and the lower plate 3 of the polishing device. The plate is made of any one of the oil and fat plates of the above, and a highly foaming liquid that generates a large amount of gas such as carbon dioxide as an abrasive, or a low viscous liquid is used for crossless polishing. It is a polishing device.

In the present invention, the lower surface 2 of the upper plate 1 on which the rotary shaft 6 is attached is made of a porous material or has a large number of small holes, and the workpiece 5 is fixed by vacuum suction or the like, and the workpiece 5 is automatically attached during machining. The lower plays 1 to 3 have a flat upper surface 4 and a shaft 7 on the lower side that can be rotated as required.
The abrasive is provided to the workpiece by an appropriate method.

As shown in FIG. 1, in the conventional example, a cloth, batt, urethane film, etc. A is fixed to the upper surface 4 of the lower plate 3 using a method such as gluing, and the lower surface 2 of the upper plate 1 is adsorbed. A method is used in which the workpiece 5 that has been polished is polished.

However, as mentioned above, they share many problems, drawbacks, and troubles, and as a result of intensive research, a crossless polishing method as shown in FIG. 2 has been arrived at.

In the present invention, the lower plate 3 can be an ultrafine particle grindstone plate, a resin plate, a metal plate using resin as a medium, an alumina plate, etc.
Soft metal plate, soft ceramic, pitch, tar,
Polishing is performed using any one of the oil plates, such as oil, but any of the above-mentioned materials may be used, and any method may be used, for example, a supply device.

Alternatively, the polishing agent supplied with a hand-held tool may be a highly foaming liquid that can generate a large amount of gas such as carbon dioxide, or a low-viscosity liquid.
A low-viscosity multifoam cream-like abrasive containing many small bubbles enters between the machined surface of the workpiece 5 and the upper surface 4 of the lower plate 3, polishing the machined surface of the workpiece 5. This is a polishing method that does not require polishing. Since the abrasive is in the form of a foam-containing cream during polishing, it will not be scattered by the centrifugal force generated by the rotation of the upper plate.

The above explanation is for a single-sided polishing device, but
Double-sided polishing equipment processes both sides of the workpiece,
That is, even if the upper plate and the lower plate are each made of the above-mentioned material and polished with the above-mentioned abrasive, the effects of the present invention do not change.

(Effects of the Invention) The effects of the present invention arise from the fact that it is clothless, which eliminates the need for fixing cloth etc. to the machined surface of each plate and troublesome re-covering, prevents surface sagging and edge sagging, and thus prevents dummy,
It eliminates the need for Yato, expands the effective area of the workpiece to the maximum, significantly improves flatness accuracy, reduces heat generation due to frictional heat, and eliminates the need for cooling water by providing a cooling device for each upper and lower plate. It is an innovative and highly practical device that has many advantages and features, such as being unnecessary and simplifying the structure of the polishing device itself.

[Brief explanation of the drawing]

FIG. 1 is a side view of the main parts of the conventional example, and FIG. 2 is a side view of the main parts of the embodiment of the present invention. 1... Upper plate, 2... Lower surface of upper plate, 3...
- Lower plate, 4... Upper surface of lower plate, 5... Workpiece, 6... Rotating axis, 7... Axis. A...Cross.

Claims (1)

[Claims] A polishing method that eliminates the cloth used in a double-sided polishing device or a single-sided polishing device for semiconductor wafers, comprising: pressing a workpiece between the lower surface of an upper plate and the upper surface of a lower plate; The upper plate, lower plate, and both upper and lower plates of the polishing device are polished using ultrafine particle grindstone plates, resin plates, metal and alumina plates using resin as a medium, soft metal plates, soft ceramics, pitch, and tar. , by polishing using one of the oil plates and a highly foaming liquid abrasive that generates a large amount of gas such as carbon dioxide as an abrasive, or a low viscosity liquid abrasive. ,
A crossless polishing method for semiconductor wafers characterized by being crossless.