Hi,

You will not get a rectangular pattern on <110> silicon wafter with
anisotropic etching by KOH or TMAH. You will probably get a
parallelogram pattern with an angle of 109 degree. The etching will
stop at two vertical <111> plane and two inclined <111> plane.

Hope it helps.
Best regards,

Fei Wang
______________
Postdoctoral researcher, Dr
MIC - Department of Micro and Nanotechnology
Technical University of Denmark (DTU)
Building 344, 1st floor, Room no. 130
DK-2800, Kgs. Lyngby
Denmark
Tel:  +45 4525 6311
Fax:  +45 4588 7762
Email: fei.wang@nanotech.dtu.dk
       http://www.nanotech.dtu.dk