Taiwan Semiconductor Manufacturing Comp. Ltd.

Shih-Shun Chen

Yuan-Ko Hwang

Hung-Hsin Liu

How-Cheng Tsai

Kwang-Chen Wu

Yu-Chih Lai

Cheng-Yi Chang

A method and apparatus for measuring a wafer position on a lower electrode in a plasma etching device are disclosed herein. A wafer is generally placed on a lower electrode in a process chamber of a plasma etching device. Such a wafer (i.e., semiconductor wafer) generally comprises a front side and a back side. A differential pressure gradient between the front side and the back side of the wafer is determined, and thereafter, a position of the wafer on the lower electrode can be measured utilizing the differential pressure gradient.

In-situ measurement of wafer position on lower electrode

A method of forming very small silicon nitride spacers in split-gate flash EPROMs is disclosed which prevent the occurrence of &ldquo;write disturb&rdquo;, unwanted reverse tunneling, or erasing. This is accomplished by forming spacers with well controlled dimensions and well defined shapes through a judicious combination of dry etch with wet over-etch technique. The wet etch along with the dry etch widens the process window from a few seconds to several minutes so that the small dimensioned silicon nitride spacers can be better controlled than it has been possible in the past. In a second embodiment, the step of over-etching of the spacers is combined with the step of stripping off of an implant photomask, thus, shortening the manufacturing product cycle.

Method of forming tiny silicon nitride spacer for flash EPROM by using dry&plus;wet etching technology

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Hsinchu, Taiwan

Shih-Shun Chen