Dear colleagues:
I want to construct a silicon nitride microbridge above the Si
substrate. Polyimide is used to be the sacrificial layer. I have two
groups of questions below:
1)Is PECVD or RF magnetron sputtering(not reactive sputtering) Si3N4
suitful for constructure layer of microbridge? How to lessen the stress
of the film during the process?
2)When pattern polyimide, how to dry-etch polyimide and control the
angle of the side wall in the process? Is dry-etching better than
wet-etching using alkaline reagent? When I wet-etch polyimide, there
always have a protrusive ring around the rim of the patterned hole, any
one can tell me how to prevent it? How to release polyimide after the
bridge has been patterned?
Any information will be sincerely appreciated. Thank you all in advance.

--
Ma Bin
500, Chi Feng Road
Shanghai Institute of Technical Physics
The Chinese Academy of Sciences
Shanghai 200083
P.R.C.

Email: mabin@online.sh.cn