Adhesive wafer bonding for CMOS based lab-on-a-chip devices

Adhesive wafer bonding using laminated photosensitive dry-resist offers many advantages and can be used to realize advanced, CMOS integrated, volume manufacturable lab-on-a-chip devices. The relatively low bond temperatures involved allow the wafer-level hybrid integration of a range of substrates, e.g. CMOS wafers with structured MEMS glass wafers. The dry-film polymer acts as the adhesive interlayer and can also be lithographically patterned to form sealed microfluidic fluid channels and chambers after the bonding process.

We have implemented a baseline 8” process flow for the adhesive bonding of a micromachined glass-wafer to a CMOS substrate using the ORDYL SY300 series of permanent dry-film photoresist, and gained some first experience during the sample fabrication of several thousand chips in a commercial cleanroom setting. A brief review of published work will be given, and we will share some of our recent observations on the topic of adhesive wafer-level bonding using permanent dry-film resist.