Evelyn
What metrology tool were you using and how did you use it.
Also what was the Ti thickness.
Shay

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Evelyn B
Sent: Wednesday, April 29, 2009 1:05 AM
To: General MEMS discussion
Subject: [mems-talk] Ashing effects

To all,

I measured the average thickness of a Ti/Pt stack-up on a Si wafer at three
different locations as summarized below:

                  *  Before ashing        After ashing      Delta*
Structure #1: 139.7 nm              219.00 nm         79.30 nm
Structure #2: 122.5 nm              199.75 nm         77.25 nm
Structure #3: 117.0 nm              200.00 nm         83.00 nm

After doing the ashing I did not observe any damage to the Pt layer but
can't explain the increase in thickness above, especially when I had already
calculated an etch rate of 11 nm/min and had only etched for 3 minutes.  The
ashing recipe is 150 W, 44 sccm, 250 mT for 3 minutes in O2 plasma (PE
mode).

Can anyone think of anything that could cause a change of 80 nm in
thickness?

--
EVELYN BENABE