Thermal Stability of Shallow Ge N+-P Junction with Thin GeSn Top Layer

Abstract

Thermal stability of the Ge N' -P junction with thin GeSn top Layer is evaluated in this work. Thin GeSn itself would not increase junction leakage current although its bandgap is narrower than Ge. However, high dose ion implantation would damage the GeSn layer and Ge substrate so that the diffusion coefficient of Sn atom in Ge is enhanced. In this case, thernial annealing higher than 500 C would degrade junction leakage current. It is thus suggested that low defects doping technique must be developed.