The best way to etch Si3N4 is by plasma (dry etch) and you can use
photoresist as a mask. Oxide cannot be used for a mask because it is too
similar in composition and will not provide a good mask

-----Original Message-----
From: Krishna Vummidi
Subject: [mems-talk] reg: wet etching Si3N4

Is it possible to wet etch Si3N4 using photoresist as a mask. or do we
need to have SiO2 as the mask. and is there a simpler wet etching
technique unlike the usual controlled bath. the thickness is around
2000A.