An iteration approach for base doping optimization to minimize the base transit time in triangular-Ge-profile SiGe HBTs

This work presents a fixed-point iterative approach to optimize the base doping profile inside the base of triangular-Ge-profile SiGe HBTs to achieve the minimum base transit time. The results show a consistent reduction in base transit time with increasing slope of triangular-Ge-profile in base region in conjunction with an optimized base doping profile. Moreover, the optimum base doping profile shows a continuous reduction in base Gummal number for an increasing Ge-slope inside base. The iterative methodology is extended to incorporate the shifted-Ge-profile approach in base to achieve further reduction in base transit time.