Salut,

>
> Does anybody know which gas is suitable for dry etching platinum ?

For what application do you need Pt? If the sidewall slope does not
matter and the feature size is high try simply Ar. If you need a steep
slope without fences things get "very" difficult. You have to use
hardmasks and Cl2 processes and so on...

Pt etching is a sputter dominated process. You do not have a chemical
etch component as Pt does not form volatile etch products. Thus it is
going to redeposit onto your wafer and will form -depending on you
process regime- ugly fences at the sidewall of the photoresist that will
remain after stripping the PR.

Bonne chance,

A+
Stefan Schneider