300mm wafer thinning and backside passivation compatibility with temporary wafer bonding for 3D stacked IC applications

Abstract

Thin wafer handling has become a very challenging topic of emerging 3D technologies, and temporary wafer bonding to a carrier support wafer is one way to guarantee the required mechanical stability and rigidity to the thin wafer during subsequent backside processing. The temporary bonding approach followed by Imec is based on the adhesive material HT10.10 from Brewer Science (WaferBond <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> HT-10.10). The thermal and chemical stability of the temporary adhesive layer has been fully assessed and characterized in a 300mm production line, and for the first time we report on the full integration of thin wafer handling with backside processing on 300mm CMOS wafers.