A Study of Si-Ge Interdiffusion for SiGe based Semiconductor Devices

This book focused on interdiffusion behaviors in SiGe heterostructures under different strain conditions. A unified Si-Ge interdiffusivity model without strain's impact was built over the full Ge fraction range for the first time. It was demonstrated that the unified model is valid for Si-Ge interdiffusion under conventional furnace anneals, and advanced anneal techniques such as soak and spike rapid thermal anneals. In addition, the role of biaxial compressive strain in Si-Ge interdiffusion was fully clarified. Compressive strain can enhance Si-Ge interdiffusion greatly, by tens to a hundred times at certain temperature range. Moreover, some new light was shed on a more complicated case, interdiffusion with strain relaxation. The interdiffusivity models can be employed to predict and estimate interdiffusion in SiGe heterostructures for next-generation semiconductor devices, and to optimize the design of SiGe epitaxial structures and thermal budgets for fabrication processes. On the theoretical side, these models can be used as reference lines for studies on Si-Ge interdiffusion with doping and/or with defects.