Hi Reza,

What voltage are you using for your anodic bonding process?  How thick is
your glass substrate?  If you know these quantities, you can estimate with
reasonable accuracy the electrostatic force on the membrane and determine
how far it will deflect.  Because your membrane is so thick, you shouldn't
see much deflection at all.  I'm not very familiar with anodic bonding, so I
can't tell you if you'll experience stiction or surface tension forces, but
you you shouldn't see much deflection (certainly much less than a micron)
from the electrostatic forces.

Feel free to contact me for more details or if you have any questions.

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, Feb 3, 2009 at 11:32 PM, Reza Rashidi  wrote:

> Hi everyone,
>
> I am going to anodically bond si to glass. There is a 53 um thick square
> membrane with side 1.6 mm in the middle of si chip. Also, there is a 10 um
> cavity and a gold electrode on the back of si membrane that forms a
> capacitor when bonding to a glass (Pyrex) with similar gold electrode.
> I was wondering if electrostatic force during bonding process pulls in
> membrane toward glass (as there is just a small 10 um gap between them). If
> so, does gold electorde on membrane still stick on the electrode of glass
> after the process. If not, does the membrane return to the original position
> after the process. How is the difference of effect between bonding in vacuum
> or air.
>
> Any help will be highly appreciated.
>
> Thanks,
> Reza Rashidi