Models of material parameters for strained Si/sub 1-x/Ge/sub x/ layers and study of hot-carrier transport and high frequency performance of Si/SiGe HBT

In this paper, the models of material parameters for strained Si/sub 1-x/Ge/sub x/ layers grown on <100> Si substrate and the hydrodynamics model (HDM) for Si/Si/sub 1-x/Ge/sub x/ heterojunction system are developed. Based on these models, the hot-carrier transport and high frequency performance of Si/SiGe HBT are simulated numerically. The factors that affect the cut-off frequency f/sub T/ and the optimum doping profile to improve it are discussed in detail and obtained.