SF6+O2 should work. ICP RIE or DRIE systems would be the best.

On Wed, Feb 25, 2009 at 2:32 PM, Alexandre BOE
wrote:

> 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

*  Zou Jie (Jay)
*  Department of Physics
*  University of Florida
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