Dear MEMS group!

We machine trenches with about 200um depth into a silicon wafer. The
trench width is about 30-50um yielding an aspect ratio of 1:4 to 1:7. We
want to plate the whole structure with a highly conductive metal such as
Gold, Platinum, Copper, Aluminum or Silver.  We need the trenches to be
completely covered with at least 200nm  of metal.
1. Is it possible to do that by sputtering, despite the high aspect ratio?
2. Does anyone know a method how to do that? E.g. electroless plating?
3. Does anyone have experience with such a problem?

Any hints will be greatly appreciated!

Stephan


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