Modeling threading dislocation density evolution in Ge/Si during cyclic annealing
Xuanchang Zhang, Hui Jia, Haotian Zeng, Xueying Yu, Mateus G. Masteghin, Mengxun Bai, Hexing Wang, Danqi Lei, Huiwen Deng, Huiyun Liu, Mingchu TangA compact kinetic framework is developed to describe threading dislocation evolution in Ge/Si buffers by linking the final dislocation density to the initial defect level and an Arrhenius-weighted thermal budget that captures the combined effects of temperature, annealing time, and layer geometry. Despite extensive experimental progress in Ge-on-Si integration, optimization of growth and annealing parameters remains largely empirical, owing to the lack of a framework connecting processing conditions to defect evolution. Calibrated against electron channeling contrast imaging measurements from undoped and Sb-doped Ge/Si buffers with different annealing cycle counts, the model captures the overall reduction and saturation trends across the wafer set. This compact framework provides a practical means of assessing how initial defect density and accumulated thermal exposure influence final threading dislocation levels in thin Ge/Si buffers.