Matthew,

1000A? - you may have to get to 100's of volts to get enough current through to
effect the bond - what kind of setup are you using? - you may want to try a
stepped voltage approach, 200V for 30 sec, 400V for 30 sec... etc until you've
achieved your bond (if its possible).

On the bonder I am used to (EVG520IS - we manufacture them), we use double sided
heating, and can supply up to 2000 volts (applied in a planar matter).

If you are using the most common "home made" setup, stacking the wafers on a
hotplate (glass up) and applying the negative potential as a point source. You
may be limited in voltage, and in ionic mobiity (since the heating is occurring
away from the glass, which needs the mobility), by your setup.

Best Regards,
Chad Brubaker

EV Group       invent * innovate * implement
Senior Process Engineer - Technology - Tel:  480.727.9635, Fax:  480.727.9700
e-mail: [email protected], www.EVGroup.com


-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of matthew king
Sent: Thursday, April 26, 2007 3:50 AM
To: General MEMS discussion
Subject: RE： RE: [mems-talk] will the SOI fabrication process affect the anodic
bonding

Dear Chad,

  Thank you for your reply. They say 0.8u PECVD oxide could withstand 160v and
SiO2 in SOI is mostly thermally grown. Will 100nm thmally grown oxide withstand
several tens of volts? Can the bonding proceed without making a gounding contact
if layer is thicker than 100nm?

  Sincerely yours,
Matthew King