Title :
Effects of doping and Ge fraction grading in the base on the base transit time and Early voltage of Si/SiGe HBTs
Author :
Zhang, Wanrong ; Zheng, Zeng ; Wu, Wengang ; Luo, Jinsheng
Author_Institution :
Inst. of Microelectron., Xian Jiaotong Univ., Shaanxi, China
Abstract :
The base transit time τb and the Early voltage V A for Si/SiGe HBTs with gradients of Ge fraction and doping in the base are studied. It is found that the retarding field, caused by doping grading exhibits 40%-80% contribution to τb depending on the doping level near the emitter, VA increases quasi-exponentially and τb decreases with the increase in gradient of Ge fraction in the base
Keywords :
Ge-Si alloys; elemental semiconductors; heterojunction bipolar transistors; semiconductor device models; semiconductor doping; semiconductor materials; silicon; Early voltage; HBTs; Si-SiGe; base transit time; doping effects; doping grading; fraction grading; retarding field; Capacitance; Doping; Electrons; Germanium silicon alloys; Heterojunction bipolar transistors; Microelectronics; Quasi-doping; Semiconductor process modeling; Silicon germanium; Voltage;
Conference_Titel :
Solid-State and Integrated Circuit Technology, 1995 4th International Conference on
Conference_Location :
Beijing
Print_ISBN :
0-7803-3062-5
DOI :
10.1109/ICSICT.1995.500192
