Dear Colin,
You might try using thermal or cvd oxide as a mask.  You can define
dielectric with either aluminum or Cr/Au.  Suggest you made need in the
order of 5-10 micrometers of dielectric to resist pinholing.  Another
possibility is to overcoat SiO2 with Si3N4, defined by metal.  With two
different dielectrics, that may also reduce pinholing.  Good luck.

-----Original Message-----
From: Colin Ashruf 
To: MEMS@ISI.EDU 
Date: Thursday, May 28, 1998 12:27 PM
Subject: Gold/silicon adhesion in KOH/TMAH


>Hi,
>I am a PhD student working on a new electroless etch stop technique.
>Could you help me with the following problem:
>What kind of metal process do I need to get a gold layer on silicon
>which survives KOH or TMAH at high temperatures. We have tried
>evaporated Au/Cr but that comes of after a few hours?
>If you can help me please e-mail: c.m.a.ashruf@et.tudelft.nl
>Thanks
>
>
>