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.