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Cutting Work by Wire Saw

IP.com Disclosure Number: IPCOM000199829D
Publication Date: 2010-Sep-17
Document File: 3 page(s) / 297K

Publishing Venue

The IP.com Prior Art Database

Related People

Hiroaki Tamura: AUTHOR

Abstract

The sliced wafers have contact with a saw wire when the wafers are pulled up from wire position after the ingot slicing. It generates damages on the wafer surface, and the damages appear as saw marks after etching. The yield loss by the saw marks becomes more serious on larger diameter wafers. A method to reduce the surface defects was found. This method can reduce the yield loss by saw marks caused by wire saw process. So far, it was thought that low ingot pull-up speed was better than high speed to reduce the saw mark defect. But it was detected that this does not apply. In the case of a 200 mm wafer 80 mm/min to 100 mm/min pull-up speed was better than 40 mm/min pull-up speed to reduce the saw marks. The most important point is that it is not true that the low pull-up speed is always better than the higher speed regarding the reduction of saw marks. By this method not only process yield but also process cycle time can be improved.

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Cutting Work by Wire Saw

ワイヤーソーによる切断作業方法

田村博明(Hiroaki Tamura)

   Siltronic Japan Corporation シルトロニック・ジャパン株式会社

Summary

Background

The sliced wafers have contact with a saw wire when the wafers are pulled up from wire position after the ingot slicing. It generates damages on the wafer surface, and the damages appear as saw marks after etching. The yield loss by the saw marks becomes more serious on larger diameter wafers.

Abstract

A method to reduce the surface defects was found. This method can reduce the yield loss by saw marks caused by wire saw process.

So far, it was thought that low ingot pull-up speed was better than high speed to reduce the saw mark defect. But it was detected that this does not apply. In the case of a 200 mm wafer 80 mm/min to 100 mm/min pull-up speed was better than 40 mm/min pull-up speed to reduce the saw marks. The most important point is that it is not true that the low pull-up speed is always better than the higher speed regarding the reduction of saw marks.

By this method not only process yield but also process cycle time can be improved.

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1.


1. 背景技術背景技術背景技術

背景技術

 インゴットをウェーハの形状の切断する工程では、近年マルチワイヤーソーが使われている。この時、マルチワイヤ ーソーでインゴットを切断した後に、ワイヤーからインゴットから引き抜く必要があるが、その際にワイヤーがウェーハ 表面に擦れ(図1)、ウェーハ表面を傷つけてしまうことで、その痕が後工程でソーマークと呼ばれる欠陥になり(図2)、 ウェーハの歩留り低下の一因になることが問題となっている。


2.


2. 発明発明発明

発明が

がが

が解決解決解決

解決しようとしている

しようとしているしようとしている

しようとしている課題課題課題

課題

カーボンベース

Normally saw mark

図1

After slicing wafer surface

図2

Abnormally saw mark

 引き抜き作業時に、ウェーハを傷つけないようにするためには、これまで、ワークの引き抜き速度をできるだけ遅く することが良いと考えられてきた。実際、例えば、最近の特許(特開2009-142912)においても、ワイヤーソーで切断後 のワークを引き抜く...