[mems-talk] Releasing of the nitride suspended structure

[deepak agrawal]

Can i use the dry etching to etch the Aluminum so that there will be no
chance of stiction. Is there anyone has the knowledge about dry etching
recipe of Aluminum.

<<Hi all,
I am trying to release the nitride suspended structure. In that structure I
have 1.2um thick sacrificial layer of Aluminum on a silicon substrate over
which 0.2um thin structural layer of silicon nitride deposited by PECVD
process. At the top, combined layer of chrome and gold are using to get the
top electrode. The top electrode and nitride pattern are etched by wet and
RI etching respectively.
For releasing, ortho phosphoric etchant is using to etch the Aluminum from
the active area. The sample is placed in the etchant at 60c temperature for
17 minutes followed by 10 minutes in DI water and 10 minutes in oven at
120c. I am not getting the released structure. The full pattern is sticking
with the surface of silicon. Is there any change in the process that i can
do to get the released device.>>