To Edward Chan and others interested in pull-in measurements:

Our experience is that we get 155GPA +/- 2-3% for the
poly modulus in all the MUMPs runs.  However, we will check
our datasets to see if there is anything unusual in MUMPs 22.

Were you working from fixed-fixed beams, or cantilevers?
We have identified some problems with cantilever curvature,
and are working on that problem now.  Our fixed-fixed
beams appear to be very well behaved.

/sds
--
==============================================================
Stephen D. Senturia,Weller Professor of Electrical Engineering
      Room 39-567, Massachusetts Institute of Technology
      Cambridge, MA, 02139
Phone 617-253-6869    sds@mtl.mit.edu   FAX 617-253-9606
==============================================================
Edward Chan wrote:
>
> Hi,
>
> I'm trying to determine the material properties of the polysilicon
> film (POLY1) of the MUMPs 22 run using the pull-in method of
> Gupta & Senturia (MIT).  I am getting very low values for
> Young's Modulus (110 GPa).  Biaxial stress is -6MPa.
>
> Compared to Gupta's thesis, I'm getting pull-in voltages of
> 29V for the 300um beam (compared to 50V by Gupta) and 14V for
> a 400um beam (compared to about 25V by Gupta).
>
> I've measured the film thickness (1.96um) and the gap (1.94um).
> The dice are placed in the Gel-Pak containers so no vacuum is
> applied to the back.
>
> Anyone else measure such values?
>
> Thanks!
>
> +=========+=====================+===================================+
> | Edward  | Tel: (650) 723-1482 | CISX 305, Stanford, CA 94305-4075 |
> |  Chan   | Fax: (650) 725-7731 |     chan@gloworm.stanford.edu     |
> +=========+=====================+===================================+
>