Dear MEMS coworkers,

We currently utilize foundry service to fabricate our MEMS platform, and we
functionalize the platform by coating a proprietary material. The existing
platform design calls for, fresh out of foundry, a SiO2 top layer with
contact openings to the underlying Al.

The issue we run into is that the exposed Al is easily oxidized and the
contact resistance varies from sample to sample. We have tried using
chemistry removing the aluminum oxide layer prior to functionalization. Yet
the oxidation happens so rapidly that a  thin insulating oxide is formed
between sample transfer (in air), so we alleviated but not eliminated the
reproducibility difficulty.

I appreciate any insights.

Regards,

Barry Chen