Dinesh,

A quick search on scholar.google.com using "wet etching of tungsten silicide" as
the search parameter will give you many papers and patents of some use.

I will tell you, however, that Intel abandoned completely attempts to use
tungsten silicide during process development work in the very early 1980s.  The
tungsten source was WF6, and the fluorine which evolved during the deposition
formed HF vapor, which created shorts between the polysilicon gate, and either
the channel, or the source-drain.  The parasitic HF etch was driven by
mechanical stress, and could not be controlled or eliminated.  A different
silicide was chosen, in order to reduce source-drain and poly-gate resistance.

Al Henning
Director of MEMS Technology
NanoINK, Inc.

-----Original Message-----
From: dineshan ak [mailto:dineshan_ak@yahoo.co.in]
Sent: Thursday, April 21, 2011 4:24 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Wet etch of WSi2

Hi all,

I am looking for a chemical solution to perform wet etch of tungsten silicide
layer.

I am working on gate oxide pinhole failure analysis and my gate is polysilicon
with WSi2 on top of it. i have tried HCl, H2O2 and SPM to etch Wsi , but was
unsuccessful. The conventional way of removing Wsi2 is polishing. But it will
induse damages to polysilicon. I also can not go for plasma etch as it will
casue damage to poly.

Can anyone please suggest some chemical for tungsten silicide etch. thanks a
lot.

Dinesh