I have been trying to get sharp corners on (110) si wafers but till now i
haven't had any successs.
One paper you might find interesting is Aqueous KOh etching of silicon
(110), By Byungwook kim. journal of Electrochemical society, vol 145, no.
7 july 1998. email me if you can't find the paper and i can send the pdf.

new simulation tool Etch3D by coventorware can tell you how the wet
etching will go on different orientations.

Rahul Agarwal
Phd candidate
University of south florida