On Apr 18, 2005, at 7:03 AM, jedidi nader wrote:
> ...deposit of silicon nitride by LPCVD. I would like to know why it
> would be necessary to sweep the tube with NH3 before and after the
> deposit of nitride ?
>

As I recall from the engineer who set up our process, this flow of NH3
before the DCS starts and after the DCS is shut off is to make sure all
the DCS is reacted away to avoid ammonium chloride from remaining in
the tube or on the wafers.

-Jim Beall