Influence of Composition of SiCN Film for Surface Activated Bonding

Surface activated dielectric bonding is more and more attractive as a key technology to realize further high performance CMOS based devices independent on scaling. The major challenge of dielectric bonding is to decrease the process temperature in order to be compatible with CMOS processing. Although the conventional SiO2-SiO2 bonding has already been comprehensively investigated, there might be some limitations in terms of thermal budget. In the past, we have demonstrated low temperature bonding using PECVD-SiCN as interfacial layer, where we have obtained more than 2200 mJ/m2 of adhesion energy at 250 °C of post annealing. In this work, the composition of SiCN has been tuned aiming at the identification of the key elements taking part in the bonding mechanism and to further increase the adhesion energy at low post bond annealing temperature.