Subject: Re: UVN-30 and GaAs
From: Mahnaz Mansourpour <mahnaz@snf.stanford.edu>
Date: Mon, 22 Sep 2003 09:26:12 -0700

Hi Kai,

I have another adhesion promoter , come and see me . It worth trying it.

mahnaz

Kai-Mei Camilla Fu wrote:

> There was HMDS on all samples, deposited using the YES oven.  The SNF
> process sheet was followed for UVN-30 which includes HMDS.
>
> On Fri, 19 Sep 2003, James Conway wrote:
>
> > 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
> > SNF
> >
> > 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
> >