Hi, if you have experience in deep reactive on etching, and especially on
SOI wafers, it would be great if I could borrow your experience and get
your advice.

Q1: did you ever experience huge "bowing effect"? what mask you used in
this case, SiO2 or PR?
Q2: did you ever have serious "footing or notching effect"?
Q3: If an SOI is glued by PR with a dummy wafer, and the whole sandwich is
put into the DRIE chamber for etching, what do we expect?
Q4: if we have hardbaked PR on the back side of an SOI while the other side
is for etching, what effect does this PR layer play? In essence, what would
happen if the layer of Si for ecthing has a temperature higher than normal?

Thank you very much.

Best,

Sun