Characterization of wafer-bonded substrates for advanced channels in Si-based MOSFET

Wafer bonding is an attractive process to install new structures and materials, alternative to conventional bulk-Si substrates, to the CMOS channel layers on a Si platform. Although the process seems to be mature in the production of commercial silicon-on-insulator (SOI) substrates, careful consideration should be given to the case of hetero stacking structures, especially to the bonded interface which should have device grade quality. In this work, crystallinity, heterointerface chemistry, and electrical property are thoroughly analyzed by using advanced characterization tools for direct Si bonding (DSB) and germanium-on-insulator (GOI) substrates as prototypical wafer-bonded substrates.