Hi!!! All

I want help of urs.I am making cantilever and want to study properties of it by
applying potential accross it.
For these i m taking P- P+ wafer means i m taking P- at from side and
backside is P+ which I want to use as ecth stop while ecthing of P- for
freeing beams.
First of all I grew oxide on P- and over that i did Aluminium
deposition.Than I m doing lithography for getting beams pattern on
Aluminuim.This  oxide and Aluminium both  will work as mask while removing oxide
except beam area.So after removal of oxide silcon will exposed and there will
left some beams pattern having oxide overthere will be Aluminium .Metal
deposition i m doing so that i can apply force and can study its behavior.
After getting patterns on Aluminium film i m able to etch Alumium .
But my problem begins now As I wanted to remove oxide so that my Silicon can be
exposed and Aluminium should be there .
As first i use BHF it was attacking photoresist and than Alumium was also ecthed
out .I have tried after changing ratio of ammonium floride and Hf.But still it
doesn't solve.
So I need ur help if any one can help me.
Hope for the prompt reply.
Saroj
Physics Dept
IISC ,Bangalore