Structural change of direct silicon bonding substrates by interfacial oxide out-diffusion annealing

The use of Si(011)/Si(001) direct silicon bonding (DSB) substrates is a key for future complementary metal-oxide-semiconductor device technology. In conventional bonding process, it is necessary to remove interfacial SiO2 to achieve direct atomic bonding. In this study, using X-ray microdiffraction and transmission electron microscopy, we investigate the structural changes caused by oxide out-diffusion annealing (ODA). It is revealed that crystallinity of the bonded Si(011) layer is degraded after low temperature ODA and gradually recovered with an increase in the ODA temperature and time, which is well correlated with the interfacial SiO2/Si morphology. Characteristic domain textures depending on the ODA temperature are also detected.