Shane:

You are probably creating a CrOx which is changing the resistance in your
via. I would suggest etching with the CF4+O2 thru 90% of your SiO2 film then
shutting off the oxygen for the remaining 10% of the film. This should help
eliminate the oxidation of the Cr and give you a lower contact resistance
measurement.

Bob Henderson

----- Original Message -----
From: "liuxf" 
To: 
Sent: Monday, October 13, 2008 9:20 AM
Subject: [mems-talk] RIE for SiO2 and its effect on Cr underneath


> Dear All:
>
> I am trying to etch SiO2 on top of a Cr pillar. Actualy the SiO2 is a
passivation layer and I wanna open a via on top of the Cr pillar. I used CF4
and Oxygen. After that I found the resistance is too large. Is it possible
for Cr to form some resistive chemicals after this process?
>
> Thanks a lot.
>
> Probably I would try CHF3 but now it is not available.