Hi Roger Brennan,
you can try HF in an ultra sonic bath, I hope your device can stand it
good luck, Carel Heerkens

Roger Brennan wrote:

>Concentrated HF is the only etchant I know that removes silicon nitride
>without much damage to silicon.  However conc HF is much too slow.  Is there
>an etchant that removes nitride quickly but does not harm silicon?
>
>Thank you in advance.
>
>
>