Dear all,

We would like some advice on the best insulator layer to withstand the
following process steps:

1. HF/ethanol etch for a few minutes,

2. toluene at 190 C for 4 hours.

As this insulator will be on already fabricated FETs any temperature steps
cannot be too high. We have tried (unsuccessfully) photoresist (S1813 and
AZ4562), spin on glass and polyimide. We can do PECVD oxide and nitride, but
these will come off instantly in the HF. Would we similarly be wasting our
time with any sputter coated oxides deposited elsewhere - ZnO, TiO2?

Any help for process suggestions with existing materials, or new options,
would be useful.

Many thanks,

David Wood,
Reader,
School of Engineering,
University of Durham,
South Road,
Durham,
DH1 3LE.

Tel: +44 191 334 2464
Fax: +44 191 334 2407

email: [email protected]