Hi there,

I am trying to release a comb drive structure etched by deep reactive ion
etching (DRIE) on a SOI silicon wafer. I try to make very thin gaps between
the comb drives to have a large electrostatic force. Since the spring
constant of my supporting structure is small I get problems when I release
the chips in buffered hydro-fluoric acid (BHF). The adjacent combs stick
permanently and the device is broken. I also tried critical point drying,
the yield is little higher but not satisfactory. Who knows about another,
more gentle method to release my combs?

Thanks a lot,
Alexander