Metal bonding with ultra-thin layer for optical applications

Adhesive bonding is a well-known technics to assembly dies or wafer on a host substrate through polymer or solder bumps. To combine electronic and photonic systems on a single chip, we propose hereby to use AuSn alloy as bonding medium combined to waferscale technology and post-bonding III-V processing alleviating so the need of alignment accuracy between wafers. For instance, high density LED’s array could be realized on driving CMOS wafer taking benefits from the nice electrical, thermal and mechanical properties of this alloy. We present our first technological results using patterned thin bonding layer made of a multilayer Au-Sn composite.