silicon wet etching question

Dear Labmembers,

I have a question for you on silicon wet etching. I would like to
create an array of slightly tilted ramp surfaces in silicon. The tilted
surfaces are 50 um by 50 um with a bottom surface that is tilted by 3
degree from wafer surface, so that one side has a depth of 2.5 um and
the other side has a depth of zero. The small surface should be
optically smooth for optical purposes. I wonder if this can be done
simply by patterning and wet etching silicon using KOH etch with a
silicon wafer that is cut 3 degree off (111) orientation. It appears to
be an easy task to do, since the starting surface is so close to the
final surface (only etch down 2.5 um on one side of the ramp). But I
have been warned that it may not be easy to do.

Has anyone done this before? Do you think this approach would work?
Would the final surface be optical quality, or the ramped surface might
have a lot of steps? Thanks.

Merry Christmas!

Ben