Thanks for your answers.

I thought about XeF2 dry etching but unfortunately :

1. We do not have easy access to this equipment up to now,
2. According to the data I found in the literature on MEMS material
etching, LPCVD silicon nitride (more or less stoechiometric) seems to be
etched by XeF2.

In our case, we have beams made of LPCVD silicon nitride with width
ranging between 10 and 30 µm and I am afraid of the etching of the beams
during the release step (according to the same data, the release of 10
µm-width beams would take approximatively 20 mn). Perhaps, some nice
parameters (etching pressure and time cycle) can improve the selectivity
(Si3N4 / Si) ?

Thanks in advance,

Alexandre

David Springer a écrit :
> Hello Alexandre
>
> Using XeF2 to etch your silicon would be the perfect solution to you problem.
Exactly how to do it will depend on the type of silicon nitride you are using
and how much attack you can tolerate.  Please feel free to contact me if you
have any questions or want to try it.


--
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