I am trying to fabricate a flow channel with vertical side walls using a
<110> Si wafer.  When I etch all the way through the wafer (which is
desired) the side walls are slanted.  The wafers are coated with SiO2 and
Si3N4 as protective barriers during etching.  I expected to lose several
microns vertically during etching but the slanted walls were unexpected.

Thank you,
Connie Smith
Rice University
Department of Chemical Engineering
6100 Main MS 362
Houston, TX  77005