Kai Hiltmann wrote:
>
> > Date:          Tue, 20 Oct 1998 09:22:54 -0400
> > From:          andrew lyon 
> > Subject:       what am i doing wrong with ti adhesion layers?
> > To:            [email protected]
> > Reply-to:      andrew lyon ,
> > [email protected]
>
> > What am i doing wrong with Ti adhesion layers?  I am thermally
> > evaporating 50-100nm Au films on glass substrates with 2-5nm Ti
> > adhesion layers.  After a few days, the films turn from reflective
> > Au to a frosty white color.  Is this titanium oxidation or some
> > other diffusion process I am unfamiliar with?
> >
>
> Dear Andrew,
> your description is really pointing in the direction of Ti oxidation.
> I do not have experience wit Ti adhesion layers myself but I have
> observed similar effects with Cr. As I found later, these have also
> been described in literature as you may see from the short list below.
>
> Cr or Ti diffuse through the Au film along the grain boundaries and
> oxidize at the Au surface. This way, the surface acts a sink for the
> underlying metal film and with time passing suck up the whole adhesion
> layer. From my own experience I know that the colour of the gold film
> clearly changes even with thinnest oxide films on it.
>
> Yours, Kai
>
>