Nothing survives during KOH etching??
It is impossible.
I used Si3N4 to be the mask that can resist KOH etching until the wafer is
etched through(300um, 4~5 hours). The nitride (0.3um) is still there.
You can use oxied also but it has to be thicker .
Lung-hao Hu
Graduate Student
Dept.of Mechanical Engineering
Univ.of Colorado Boulder