The effect of base dopant out-diffusion and undoped SiGe or Si spacer layers at both sides of the base on the characteristics of microwave Si/SiGe/Si HBT´s

Author

Zhang Wan-Rong ; Hai-jiang, Liu ; Li-xin, Wang ; Dong, Wang ; Zhi-Guo, Li ; Yao-Hai, Chen ; Jianxin, Chen ; Guang-Di, Shen

Author_Institution

Dept. of Electron. Eng., Beijing Polytech. Univ., China

fYear

2002

fDate

17-19 Aug. 2002

Firstpage

66

Lastpage

69

Abstract

The effect of base dopant out-diffusion and undoped (i-) SiGe or Si layers at both sides of the base on the characteristics have been studied by device simulator ISE-TCAD. It has been found that small amounts of base dopant out-diffusion from heavily doped bases will degrade DC and frequency characteristics. The insertion of an i-SiGe layer at both sides of the base can improve collector current, current gain β and cut-off frequency f_T, the insertion of an i-Si layer between emitter and base and an i-SiGe layer between the base and collector can also improve β and f_T. These simulation results promise more freedom in the design of HBTs.

Keywords

Ge-Si alloys; diffusion; elemental semiconductors; heavily doped semiconductors; heterojunction bipolar transistors; microwave bipolar transistors; semiconductor device models; semiconductor materials; silicon; DC characteristics; ISE-TCAD device simulator; Si spacer layers; Si-SiGe-Si; base dopant out-diffusion; collector current; current gain; cut-off frequency; frequency characteristics; heavily doped bases; microwave Si/SiGe/Si HBTs; undoped Si layers; undoped SiGe layers; Annealing; Cutoff frequency; Degradation; Germanium silicon alloys; Heterojunction bipolar transistors; Performance gain; Semiconductor process modeling; Silicon germanium; Stability; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave and Millimeter Wave Technology, 2002. Proceedings. ICMMT 2002. 2002 3rd International Conference on

Print_ISBN

0-7803-7486-X

Type

conf

DOI

10.1109/ICMMT.2002.1187636

Filename

1187636