Dear Laetitia,

In general a combination of Ti adhesion layer (20-30nm) and Ag seedlayer
(50nm) works fine. Depending on the contacting method of the wafer, a
current ramp is recommended as well as substrate agiation.

Remarks to seedlayer:
Do you wish to remove the copper structures from the substrate ? This
has a certain impact on the choice of the seedlayer (e.g. etching
selectivity)
Some photoresists have weak adhesion to certain seelayers and thus
require adhesion promotors. Do you transfer the microstructures into the
silicon before electroplating.

Remarks to desired properties of electroplated copper.
The composition of the copper electrolyte is depending on the properties
of final copper in terms of surface roughness, hardness, thickness,
deposition speed, etc...
Again, the presence of photoresist on the wafer has to be kept in mind.

There are a lot details to be discussed to give a valuable answer.

The good news about it is:
applied microSWISS is a experienced producer of high aspect-ratio
microstructures (e.g. SU-8) in copper (planar coils) and nickel
replication-tools.

Please feel free to contact me at:
 [email protected]
so we can continue with the specifications in more depth and more
confidentialty. I'm looking forward to hearing from you to provide a
good solution.


Best regards,

Roger Bischofberger
applied microSWISS GmbH
Schoenfeldstrasse 7
CH-9470 Buchs
Switzerland
Tel: +41 81 740 0424
Fax: +41 81 740 0425

++ microstructures in silicon and metal ++
++ microstructured replication tools ++


>
> ------------------------------------------------------------------------
>
> Subject:
> [mems-talk] electroplating of Cu on Si wafer????
> From:
> "Laetitia Philippe" 
> Date:
> Fri, 24 Sep 2004 11:51:46 +0200
> To:
> 
>
>
>Hi everbody,
>
>who could give me the most straightforward receipe to electroplate Cu
>on Si wafer
>1) which seed layer, Ti and Gold? is Ti or CR usufefull for adheison
>properties?
>2) which electrplating solution and which current density?
>
>thanks
>
>
>
>Dr Laetitia Philippe
>Electrochemistry and Micro-patterning Group
>EMPA
>
>Feuerwerkstrasse 39
>CH-3602 Thun
>
>Tel 41 (0)332285249
>
>
>