Wafer chuck

Abstract

The influence of the slurry generated when polishing an orientation notch and the like is minimized. The holding members 10, 20 for holding the outer periphery of the wafer W and the driving mechanism 30 for driving the holding members 10, 20 all together in the closing direction are integrally combined.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to wafer chucks suitably used particularly when polishing an orientation notch and the like of the outer periphery part of the semiconductor wafer. [0003] 2. Description of the Related Art [0004] The semiconductor wafer (hereinafter referred to simply as a wafer) has a V-shaped or a circular arc shaped orientation notch formed on the outer periphery. It is to be noted that the notch may be a linear orientation flat. [0005] When forming the orientation notch in the wafer, the polishing pad contacts the outer periphery of the wafer along a predetermined trajectory so as to create a predetermined angle, which wafer is normally attracted to and fixed to the vacuum chuck that uses vacuum, (e.g., Japanese Laid-Open Patent Publication No. 2-180554 and Japanese Laid-Open Patent Publication No. 2002-28840.). That is, a concentric or a radial groove communicating to the vacuum source is formed on...

AI Technical Summary

Benefits of technology

[0008] The present invention, in view of the problem of the conventional art, aims to provide a wafer chuck that suppresses the influence of the slurry produced when polishing the orientation notch and the like of the outer periphery part to minimum by arranging holding members for mechanically holding the outer periphery part of the wafer.

[0018] According to the configuration of the present invention, the holding member is driving all together in the closing direction towards the center of the wafer by way of the driving mechanism to push the outer periphery of the wafer in the radial direction and mechanically hold the wafer. That is, in such state, since the wafer is held with both surfaces floating in the air, even if slurry produced when polishing the orientation notch or orientation flat of the outer peripheral part is attached, the slurry can be easily removed in the post-process of washing and the like, and thus does not cause defects on the wafer. When a plurality of holding members are driven parallel to the wafer all together by the same stroke towards the center of the wafer by way of the driving mechanism, each holding member applies the same pushing force parallel to both surfaces of the wafer towards the central part of the wafer in the thickness direction, thereby preventing localized distortion or curve of the wafer.

[0019] Each holding member holds the wafer by way of the elastic member, and thus the pushing force is suitably dispersed and applied to the outer periphery of the wafer to minimize the localized distortion produced in the wafer. Further, the V-shaped groove formed in the elastic member sandwiches the outer peripheral part of wafer in a snapping manner and holds the wafer in a further stabilized manner. The guide groove formed in the opening direction of the V-shaped groove accurately guides the outer peripheral part of the wafer and allows the same to enter therein when the holding members are driven towards the center of the wafer.

[0020] The chuck according to the present invention does not require a vacuum chuck for fixing the wafer, and thus is configured to be light as a whole, and the V-notch or Orientation flat is particularly suitable in an application of polishing the notch. When polishing the internal part of the V-notch or Orientation flat, the wafer tends to perform a complex and precise movement by way of the chuck, and thus if the chuck is light weight, the driving mechanism for moving the chuck can be simplified.

Problems solved by technology

According to the conventional technique, when slurry (mixture of fluid polishing agent containing abrasive grain and powder polishing waste of the wafer) enters the lower surface side (attraction surface side) of the wafer, microscopic defects are unavoidably created at the wafer since the vacuum chuck attracts the wafer using vacuum.

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