>
> We are etching deep pits (50-100
> microns) into Si using acid (HF-HNO3-
> CH3COOH) etch. There is no problem with bare silicon, but when the wafer
> has a mask of Ti/Au then a strong texture develops on the etched surface.
> This is likely due to an electrochemical process or to contamination
> of the etching solution. Before switching over to KOH, does anyone have
> any ideas on the cause of the texture and its cure??
>
>

We used Cr/Au as a mask for this type of etchant and did not get any
texture on the surfaces.

Alex Hoelke
University of Cincinnati
MEMS group
>