Dear all,

We would  like to etch silicon (top layer of SOI wafers) using dry (or
wet) etch. We would like to get a good selectivity of this etching
solution with LPCVD silicon nitride (and PECVD silicon dioxyde, but less
important).

Up to now, we are using SF6 plasma. Si3N4 beams are defined on the top
Si layer. When the top silicon layer is etched, the SiO2 is an etch stop
layer and then the RIE etches underneath the silicon under the beams and
then releases them.

Any idea or suggestion for an etching solution (we prefer dry etch to
avoid a CPD step).

Thanks,

Alexandre

--
Dr. Alexandre BOE
Post-doctoral researcher

Université Catholique de Louvain

FSA/ELEC/EMIC - Laboratoire d'hyperfréquences

Bâtiment Maxwell b.207
Place du Levant, 3
B-1348 Louvain-la-Neuve
Belgium

alexandre.boe@uclouvain.be
Tel.  +32 10 478 106
Fax   +32 10 478 705