Polishing apparatus

Abstract

A polishing apparatus according to the present invention includes a polishing tape (41) having a polishing surface, a substrate holder configured to hold and rotate a substrate (W), a press pad (50) configured to press the polishing tape against a bevel portion of the substrate held by the substrate holder, and a polishing-tape feeding mechanism (45) configured to cause the polishing tape to travel in its longitudinal direction. The press pad (50) includes a pad body (53), a plate-shaped pressing section having a pressing surface (51a) for pressing the bevel portion of the substrate through the polishing tape and having a rear surface (51b) opposite to the pressing surface, and a plurality of coupling sections (52) coupling the pressing section to the pad body. A space (S) is formed between the rear surface of the pressing section and the pad body.

Description

TECHNICAL FIELD[0001]The present invention relates to a polishing apparatus using a polishing tape, and more particularly to a polishing apparatus for polishing a bevel portion of a substrate, such as a semiconductor wafer.BACKGROUND ART[0002]From a viewpoint of improving a yield in semiconductor fabrications, management of a surface condition in a bevel portion of a semiconductor wafer has recently been drawing attention. Since a number of materials are deposited on a semiconductor wafer repeatedly to form multilayer structures, unwanted materials and damage are left on a bevel portion which is not used for actual products. As a conventional way of transporting and holding a wafer, it has been typically practiced to bring a holding member (e.g., a robot hand) into contact with a rear surface of a wafer. However, there is an increasing demand for maintaining cleanliness of the rear surface, as microfabrication technique of a device advances and a wafer having a diameter of 300 mm be...

AI Technical Summary

Benefits of technology

The present invention provides a polishing apparatus that can control the contact area and distribution of loads applied to a substrate's bevel portion. This is achieved by a polishing tape, substrate holder, press pad, and polishing-tape feeding mechanism. The press pad has a pressing surface for pressing the bevel portion through the polishing tape and a rear surface opposite to the pressing surface. The plurality of coupling sections connect the pressing section to the pad body and are arranged along a circumferential direction of the substrate held by the substrate holder. The rear surface of the pressing section has a plurality of grooves or reinforcing members to improve polishing performance. The pressing section has a shape that increases in thickness towards the center thereof. The polishing tool can effectively polish the central region of the bevel portion without excessively polishing the boundaries at both sides.

Problems solved by technology

Since a number of materials are deposited on a semiconductor wafer repeatedly to form multilayer structures, unwanted materials and damage are left on a bevel portion which is not used for actual products.

Under such a background, the unwanted materials and damage, left on the bevel portion, are likely to come off the wafer during various processes and can adhere to a surface of a device.

Such materials, attached to the device, can affect a yield in products.

This makes it difficult to polish the central region.

In such a case, if polishing is performed for the purpose of completely removing a film or an organic substance (stain) on the central region, the boundaries are excessively polished.

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