Yan Cheng, Contact Wing Luk at IMAT Inc

"With breaking vacuum between Cr or Ta with Copper layer, the adhesion is
poor.
They have a lot of experience on this.

They recommend that you use "Ta" instead of "Cr". They do have process
developed
for your needs if your OK with Ta. They are using one pass process if the
copper
layer is less than 4,000A. The "Ta" layer thickness recommend 250A or 300A."

They have done thousands of copper seed wafers with Ta underneath.

1-360-356-5600 x 21
[email protected]




On Mon, 16 Sep 2002 16:11:59 +0200 Yan Cheng
 wrote:

> I am considering to sputter the Cu on Silicon,
> with the Cr as adhesion
> layer. The silicon will be thermal oxided 100
> nm at first.
>
> With my knowledge, the adhesion of copper
> evaporated on silicon is very
> poor. Sometimes even with Cr as the
> intermediate layer, there are some
> problem either with the poor adhesion between
> the copper and the
> chromium (with breaking vacuum to change the
> evaporation sources), or
> with poor adhesion between the chromium and the
> silicon (without breakig
> vacuum).
>
> Did anyone have the experience that the thermal
> oxide layer would help
> to the adhesion? Will there are any possible
> problems and suggestions
> for the process which I prepare to do? Thank
> you.
>
> Yan Cheng
>
>
> University of Kassel
> Email:  [email protected]
>
>
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