Direct Al-Al contact using low temperature wafer bonding for integrating MEMS and CMOS devices

This paper investigates the feasibility of direct Al-Al contact using low temperature wafer bonding process for the integration of MEMS and CMOS devices. Sufficient mechanical strength oxide-oxide bonds can be achieved using an oxygen plasma assisted low temperature wafer bonding process, with Al structures present on the bonding surface. An average contact resistance of 2.6x10^-^8@Wcm^2 was measured from single contact test structures, indicating that the establishment of direct Al-Al interconnect during the bond anneal step is possible.