Subject: Re: UVN-30 and GaAs
From: James Conway <>
Date: Fri, 19 Sep 2003 18:18:28 -0700

Please use HMDS prime on all III-V substrates after complete substrate cleans
and careful N2 blow off.

Standard practice everywhere...

All the best,

James Conway

Kai-Mei Camilla Fu wrote:

> Hello,
> After a bit of frustration with wandering features, someone finally
> suggested that I do my process on Si and GaAs at the same time.  I did the
> SNF process for UVN-30 on raith on Si, GaAs, and GaN this morning and
> found that the Si sample did not have any adhesion problems.  ON the GaAs
> sample I was able to find bits of patterns.  On the GaN sample I was able
> to find a part of the dose array somewhat intact. I varied the doses from
> 2-20 uC/cm^2 and most features were overexposed.
> I feel like this would be interesting information for future users of
> UVN30.  I am not sure if there is a way to get around this adhesion
> problem with GaAs but the current SNF process does not work for GaAs or
> GaN.
> If you have any suggestions please let me know.  Someone suggested I try
> spinning HMDS on myself.  Since I thought the YES oven was optimized for
> HMDS I am a bit weary of trying this, but if you have had experience with
> better adhesion by spinning I will certainly give it a try.
> Kai-Mei