Dept. of Electr. Eng., National Taiwan Univ.Chang, S.T.S.T.ChangLiu, C.W.C.W.LiuLin, C.H.C.H.Lin2007-04-192018-07-062007-04-192018-07-062001-12http://ntur.lib.ntu.edu.tw//handle/246246/2007041910021390An analytical equation of the base transit time including the effects of minority carrier recombination lifetime and velocity saturation for Si/SiGe HBTs with different Ge profiles has been derived. The reduction of recombination lifetime in the neutral base region due to the heavy base doping can shorten the base transit time, while the finite saturation velocity degrades the base transit time, as compared to infinite saturation velocity. The optimum design of Ge profiles in the base to minimize the base transit time can be obtained by the analytical model.application/pdf253629 bytesapplication/pdfen-USjournal article10.1109/APMC.2001.985632http://ntur.lib.ntu.edu.tw/bitstream/246246/2007041910021390/1/00985632.pdf