The doping profile function of a double base epilayer is constructed according to drift-diffusion theory. Then an analytical model for the base transit time τb is developed assuming a small-level injection based on t...The doping profile function of a double base epilayer is constructed according to drift-diffusion theory. Then an analytical model for the base transit time τb is developed assuming a small-level injection based on the characteristics of the 4H-SiC material and the principle of the 4H-SiC BJTs. The device is numerically simulated and validated based on two-dimensional simulation models. The results show that the built-in electric field generated by the double base epilayer configuration can accelerate the carriers when transiting the base region and reduce the base transit time. From the simulation results, the base transit time reaches a minimal value when the ratio of L2/L1 is about 2.展开更多
基金Project supported by the National Natural Science Foundation of China (No.60876061)the Pre-Research Project (No.51308040302)
文摘The doping profile function of a double base epilayer is constructed according to drift-diffusion theory. Then an analytical model for the base transit time τb is developed assuming a small-level injection based on the characteristics of the 4H-SiC material and the principle of the 4H-SiC BJTs. The device is numerically simulated and validated based on two-dimensional simulation models. The results show that the built-in electric field generated by the double base epilayer configuration can accelerate the carriers when transiting the base region and reduce the base transit time. From the simulation results, the base transit time reaches a minimal value when the ratio of L2/L1 is about 2.
