Hi everyone,

I am using a sputtered chrome mask to etch amorphous silicon 7000A thick
with HNA system. For the HNA system I am using 32 parts Acetic acid, 25
parts nitric, 1 part Hydrofluoric acid. I have tried two different
thicknesses for the chrome mask: 1200A and 2400A. The total etch time in HNA
was for 1min and 45 secs. After the chrome mask is stripped off with CR-7,
the surface of the amorphous silicon is evidentally damaged, with what
appears to be pits etched in the surface.

My question to anyone out there is, what thickness of a chrome mask is
required to stop the HNA from getting through and damaging the amorphous
silicon?

Thankyou For your help,

James Vaughn