As others have commented, the reason for no bonding is no current.  This
can be due to three possible causes:

1 - Too much resistance in the stack - thick oxide is the most likely
reason.

2 - Open circuit - make sure that your potential source is actually in
direct contact with your stack.

3 - proper polarity - make sure that you are net negative potiential to
the glass - easiest way is to have the silicon attached to a ground, and
apply a negative potential to the glass.

What kind of bonding system (if any) are you using? This may be
something as simple as an electrode out of position.

Best Regards,
Chad Brubaker

EV Group       invent * innovate * implement
Senior Process Engineer - Technology - Tel:  480.727.9635, Fax:
480.727.9700  e-mail: c.brubaker@EVGroup.com, www.EVGroup.com


-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of ShengYi Hsiao
Sent: Thursday, March 06, 2008 1:30 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] fialed in borofloat-si bonding?

Hi everybody.

Does anyone have experience in bonding borofloat glass to silicon wafer?

I am using recipe of 1000V and 400degree celcuse in vaccume environment,

however, after applying  that bonding condition for an hour, the glass
and
the

wafer still not being bonded. Only same weak connection randomly
happened,

which results the  interfering pattern. The wafers can easily be
separated.

Does anyone know the bonding condition for borofloat glass and Si?



the FAIL experiment records are :

voltage : 1000V

temperature:  400C

pressure:  9mtorr

bonding: 1 hr

bonding current: 0.02mA (form starting to the end) ....WHY?

Charge: 0~6e-2 (form starting to the end)


Any help would be greatly appreciated.