Hafizah: I don't know about bonding but if you want to selectively remove nitride from the backside just pain photoresist on the areas you want to remain as thin as possible bake at 90 degrees centigrade in an oven then plasma etch using florine in a plasma etch system. Bob Henderson ----- Original Message ----- From: "Nor Hafizah Ngajikin"To: Sent: Monday, October 29, 2007 9:12 PM Subject: [mems-talk] SiN/SiN bonding and substrate etch > > I have a question on how and what material can be used to bond SiN (wafer 1) with SiN (wafer 2). Secondly, does anybody know what process can be used to totally remove a part of back side Si Wafer without affecting the SiN layer at the front side.