If you substrate is Si or any crystalline material you can scratch the edge
of your sample and you can use an AFM to go over the scratch and read the
height difference. Thin metal layers usually have less adhesion to
surfaces.

On Wed, Feb 18, 2009 at 11:04 AM, Kirt Williams 
wrote:

> Trying to calculate thickness from measured sheet resistance and looking up
> the bulk resistivity in a book is prone to error.
>
> The resistivity of thin metal films is typically higher than than of bulk
> material, and varies with the deposition conditions.
>
> For sputtered titanium, I have varied the chamber pressure from 2 to 20
> mTorr and seen the resistivity rise from ~0.8 to 2.7e-6 ohm-m.
>
> For a bulk value (from the CRC Hanbook of Chemistry and Physics), the
> resistivity is 4.2e-7 ohm-m, half of the lowest value that I measured.
>
>   --Kirt Williams

--
Mehmet Aykol
University of Southern California
EE - Electrophysics
Phone: (213) 821-4090