Jan,
Try a dilute HF dip as your surface cleaning operation prior to sputtering.
We use 2% HF here for 60 seconds.  Then, test a deposit this way and do not
do any kind of insitu substrate etching prior to deposit, either.

Regards,

Justin

-----Original Message-----
From: Grahmann Jan
Subject: [mems-talk] Sputtered Cr-Au layer resistance against HF

I have a pad metallization consisting of 100nm Chromium and 300nm Gold. Both
are sputtered right after each other in vacuum. The problem is, that I need
to etch with 49%HF for a few minutes and the Cr-Au layer is practically
lifted off the siliconsubstrate. The Wafers were cleaned befor sputtering
but have a native oxide layer. Does anyone know a possibility to work with
Cr-Au or another metallization which withstands the HF? I need gold on top.