Low-Temperature Direct Bonding of SiC to Si via Plasma Activation

We investigated the low-temperature direct bonding of SiC/Si via O2 plasma activation. After optimization, a high bonding efficiency of over 90% was obtained. Surface activation was achieved via reactive ion etching (RIE) O2 plasma for 30 s without significant bombardment damage. A smooth and void-free interface was observed by transmission electron microscopy (TEM), while a significant amorphous oxide layer was also detected. By increasing the annealing temperature from 150 to 300 ∘C, the amorphous layer decreased drastically from 48 nm to 11 nm. Based on systematic experiments and analysis, the mechanism of SiC/Si low-temperature plasma-activated bonding was discussed.