Thank you for all your replies.  The process these wafers undergo is
the very basic POCl diffusion doping followed by an HF etch to remove
the top layer so it seems most likely that the gas is phosphene.  One
of the issues is that these are actually unpolished and/or texturized
wafers and it may be that the wafers are just holding onto chemicals
longer than polished wafers normally do.  Either way I will be
informing my boss that my initial thought was independently verified
and these smells are *not* normal, requesting that the proper people
look into the source of the smell and find an appropriate solution.

Thanks again,
Nicolas Duarte

On Nov 7, 2008, at 12:28 PM, Oakes Garrett wrote:

> -----Original Message-----
> From: Nicolas Duarte [mailto:nbd110@psu.edu]
> Sent: Friday, November 07, 2008 5:47 AM
> 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.