Hello everyone,

I need to bond hermetically two wafers on which there are SU-8 structures
coated by a 500nm Al film (deposited by sputtering); the interface to be
bonded is therefore Al-Al. Since I need a very low temperature process (200
°C max) to avoid destroying the SU-8 structures themselves, I originally
planned to perform an adhesive bonding with an SU-8 interlayer, but it turns
out I cannot do this with our Suss SB6 bonder because of contamination
problems (uncrosslinked SU-8 is not allowed in the bonder).

Does someone know any other technique to hermetically bond an Al-Al
interface at low temperature? I suspect it should be possible to perform
some intermetallic bonding by depositing another metal layer but I cannot
find any suitable publication describing the technique for aluminum.

Thanks in advance,

Pietro