JPS63200965A - Wafer polishing device - Google Patents

Abstract

PURPOSE:To improve a wafer in quality, by installing nozzles in both upper and lower surface plates, spouting fluid out of these nozzles, and making the wafer to as to separate from both these upper and lower surface plates by dint of the fluid pressure. CONSTITUTION:Fluid is spouted out of nozzles 5 installed in an upper surface plate 1 and a lower surface plate 2, and a wafer 7 is separated from these upper and lower surface plates 1 and 2 by dint of the fluid pressure. Simultaneously with this separation, alkanine abrasives sticking to a surface of the wafer 7 are washed away, getting rid of an etching action. In consequence, occurrence of any irregularity on the surface of the wafer 7 caused by etching is made preventable.

Description

[Detailed Description of the Invention] [Summary] Spout ports are provided in the upper surface plate and the lower surface plate, liquid is jetted from the jet ports, and the wafer is peeled from the upper surface plate and the lower surface plate by the liquid pressure. , a wafer polishing apparatus designed to prevent wafers from being etched by abrasives.

[Industrial application field]

The present invention relates to a wafer polishing apparatus, and particularly to an improvement in the structure of a surface plate.

The liquid mixed with the polishing agent used in the wafer polishing apparatus is alkaline and has an etching effect.

There are many wafers on the lower surface plate after polishing, and it takes time to take them out.

Take it out for this reason! The surface conditions of wafers that are ejected early and those that are ejected late are different, and in particular, wafers taken out at the end have irregularities on their surfaces because they are etched by the abrasive.

Under the above circumstances, there is a need for a wafer polishing apparatus that can prevent the wafer from being etched by the abrasive after the polishing process is completed.

[Conventional technology]

As shown in FIG. 4, a conventional wafer polishing apparatus places a wafer 7 on a carrier 6 between two surface plates (22, 23) rotating in opposite directions and having a polyurethane polishing cloth 20 attached thereto. The wafer 7 is placed in the hole and held, and both sides of the wafer 7 are simultaneously polished by applying pressure while supplying an abrasive from the upper surface plate 22.

This carrier 6 is a thin disc made of metal or epoxy resin with an Iγ of 400 μm or less, surrounded by gears, and has a rotating sun gear 24 and an internal gear 25.
It rotates around its axis due to a combination of the rotational speeds of the internal gear 25 and the sun gear 24.

When the polishing process is completed, the upper surface plate 22 is raised and the wafers 7 on the lower surface plate 23 are taken out one by one and washed with water. However, since the number of wafers is large, the wafers taken out at the end are etched by the abrasive, resulting in uneven surfaces as shown in FIG. 3, which is enlarged 50 times.

[Problem to be solved by the invention 3 The problems with the conventional wafer polishing apparatus described above are:
After the polishing process is completed, the wafers are taken out one by one and washed with water. However, since there are a large number of wafers, the wafers taken out at the end have an etching effect because the liquid mixed with the abrasive agent is alkaline. Because of this, the surface is etched, resulting in unevenness.

In view of the above-mentioned circumstances, the present invention is designed to prevent wafers from being polished after polishing.
The object of the present invention is to provide a wafer polishing apparatus that does not cause etching by an abrasive until the wafer is taken out.

[Means for solving problems]

The above problem can be solved by installing spouts on the upper and lower surface plates.
This problem is solved by a wafer polishing apparatus according to the present invention, in which liquid is ejected from the spout and the wafer is peeled off from the upper surface plate and the lower surface plate by the liquid pressure.

[Effect]

That is, in the present invention, liquid is ejected from the spout ports provided on the upper surface plate and the lower surface plate, and the liquid is used to peel the wafer from the upper surface plate and the lower surface plate, and remove the alkaline abrasive agent attached to the wafer surface. Since the etching effect is eliminated by washing away the etching, it is possible to prevent the occurrence of unevenness on the surface of the wafer due to etching.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in Fig. 1, water is used as the liquid in this example.
Water flows through the liquid guiding path 4 provided on the upper surface plate 1 and the lower surface plate 2, and is ejected from the spout 5 located at the position shown in FIG. When water is supplied to the contact surface, the wafer 7 is peeled off from the polishing cloth 3.

As the supply continues, the surface of the wafer 7 is washed with water, and the alkaline liquid mixed with the polishing agent is washed away.

In this way, water is supplied from the spout 5 through the polishing cloth 3 to the surface of the wafer 7, and by washing away the alkaline liquid mixed with the polishing agent adhering to the surface of the wafer 7, the alkalinity of the polishing agent is removed. Since the weak etching effect is eliminated, it is possible to prevent the occurrence of unevenness on the surface of the wafer 7.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a spout on the surface plate and spouting the liquid, high-quality polishing can be achieved without unevenness on the surface that is not etched by the abrasive agent, regardless of the order in which the wafers are taken out. It has the advantage of being able to obtain wafers, and can be expected to significantly improve quality, making it extremely useful industrially.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the arrangement of jet ports in an embodiment of the present invention, and FIG. 3 is a polishing of a wafer polished by a conventional wafer polishing apparatus. FIG. 4 is a side sectional view of a conventional wafer polishing apparatus. In the figure, 1 is an upper surface plate, 2 is a lower surface plate, 3 is a polishing cloth, 4 is a liquid guiding path, 5 is a spout, 6 is a carrier, and 7 is a wafer. Figure 1: National policy showing a side cross-section showing an embodiment of the present invention National policy showing the arrangement of spout ports in an embodiment of the present invention 2
Figure 3: National policy showing the polished surface of a wafer polished with a conventional wafer polishing machine Figure 4: Side sectional view of a conventional wafer polishing machine

Claims (1)

[Claims] Spout ports (5) are provided on the upper surface plate (1) and the lower surface plate (2), and liquid is ejected from the jet ports (5), and the wafer (7) is transferred to the upper surface plate (1) and the upper surface plate (1) by the liquid pressure. A wafer polishing device characterized in that the wafer polishing device is capable of peeling off from a lower surface plate (2).