Hi Andrea,

If you have access to a spectroscopic reflectometer, you should be able to
use it to measure the thickness of your membranes.  You should check with
the manufacturer of the tool to see if your membranes fall within the
thickness range accessible to the tool and how to configure the software
film stack model.  I haven't tried this myself, but I know of at least one
manufacturer that advertises this as a capability of their product.

Another option is to use a stylus profilometer to measure the etch depth,
and subtract this from the thickness of the wafer.  The accuracy of this
measurement should be more dependent on the thickness tolerance of your
wafer than the accuracy of the profilometer itself (which is usually around
+/- 10nm).

Good luck,

Brian C. Stahl
Graduate Student Researcher
UCSB Materials Research Laboratory
brian.stahl@gmail.com / bstahl@mrl.ucsb.edu
Cell: (805) 748-5839
Office: MRL 3117A


On Tue, Jan 5, 2010 at 1:38 PM, Andrea Mazzolari wrote:

> Hi All,
>
> i need to realize silicon membranes of thickness 14 and 29 um in (100)
> silicon.
>
> I need to measure membrane thickness with a tollerance of 0.5um.
>
> Any suggestion about a way to measure membrane thickness with a so good
> resolution ?
>
> Best regards,
> Andrea