You will be using fluorine chemistry to etch the silicon.  This will not
normally attack the chrome, but you might get some sputtering of the film,
leading to micromasking and grass.  You can avoid this by leaving the resist
on over the chrome (if practical).  The best chemistry to have minimal
attack on oxide is probably SF6/O2.  Adjust the O2 and the stage temperature
to achieve the profile you need and to avoid black silicon.
Martin Walker, Oxford Instruments Plasma Technology
[mems-talk] dry etching of chrome
P. DUBREUIL mems-talk@memsnet.org  
Fri, 24 May 2002 13:14:41 +0200
We are using chrome as a hard mask to dry etch Si by DRIE ICP. > What is a
good  gaz echant that will not attack the chrome, nor  SiO2.

thanks




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