Sounds like phosphine. Probably very low concentration - otherwise, you wouldn't be writing this email. This is the gas they add to the silane or other silicone source gas to grow doped poly or phosphor-doped silicon dioxide. Shay -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Nicolas Duarte Sent: Friday, November 07, 2008 2:47 PM To: General MEMS discussion Subject: [mems-talk] Smelly Wafers I just started a new job where, after an HF etch to remove phosphor glass, the wafers have a pungent garlic smell to them. I asked my coworkers about this and they said it was "normal," but I have never encountered a wafer that had a scent. It has been my experience that where there is smell there is a contaminant so I was wondering if anyone know what the potential source of this smell may be. Nicolas Duarte