Dear Dan Chilcott,

A number of alternatives exist for wafer to wafer bonding at temperatures
around 300C. The  choice of course will depend on final required device
performance and reliability, freedom in process flow, process compatibility,
starting substrates etc. But I would consider:

1] Anodic bonding (requires a glass substrate)
2] Fusion bonding - particularly with plasma-enhanced surface activation for
low-temperature, high bond strengths
3] Metal thermocompression bonding
4] UV Epoxies (requires a glass substrate)

Please feel free to contact me if you have any questions on the application
of the above bond processes to your specific device.


Regards,
Andy Mirza
Technology Manager
Electronic Visions, Inc.
3701 E. University Drive
Ste. 300
Phoenix, AZ 85034
Tel: (602) 437-9492
Fax: (602) 437-9435
E-mail: a.mirza@elvisions.com
Web: http://www.elvisions.com

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From: dan.w.chilcott@delphiauto.com
[mailto:dan.w.chilcott@delphiauto.com]
Sent: Friday, November 12, 1999 9:52 AM
To: MEMS@ISI.EDU
Subject: Wafer Bonding


I am interested in learning about wafer to wafer bonding techniques at bond
temperatures of less than 300 degrees C.  We have developed low temperature
silicon bonding processes but I am looking for alternative methods.

The method should be suitable for wafer to wafer bonding.  The bond will not
seal a vacuum but it must form a seal which cannot be penetrated by liquids.

I am interested in what has been done at companies and Universities.