Just to clarify about optical means:

Ellipsometers and reflectometers measure blanket (unpatterned) films.
They cannot provide useful thickness or composition information for
thicknesses above about 50 nm.

Optical interferometers (Wyko, or Zygo) can be used to measure patterned
films, either single steps (using e.g. the already-suggest Kapton-tape
approach), or multiple steps/trenches (patterned lithographically, or
with a shadow mask).  Calibration is essential, and unless you have
access to a well-maintained system, with a trained operator, it will
take quite a bit of time to get a useful measurement.  But, the
technique is sound and successful, whether you're measuring a single
step in a field of perhaps only a few microns square, or many steps
simultaneously across an entire wafer.

In my experience, stylus profilometers are faster and simpler, and just
as accurate, as compared to optical interferometry, if all you want is a
couple of measurements on a wafer.

Albert K. Henning, PhD
Director of MEMS Technology
NanoInk, Inc.
215 E. Hacienda Avenue
Campbell, CA  95008
408-379-9069  ext 101
[email protected]


-----Original Message-----
From: Rick Williston [mailto:[email protected]]
Sent: Friday, February 13, 2009 10:14 AM
To: [email protected]
Subject: Re: [mems-talk] Ti layer measurement...

An optical interferometer would work, so it is possible. Zygo for one
makes a unit like this.
Most stylus profilometers will easily do this. Another technique for a
blanket Ti layer would be an eddy current system but not knowing more
about the deposition parameters, I'd assume the purity and conductivity
to be suspect and steer clear of this technique, without a little
calibration work

Rick Williston