TY - JOUR
T1 - Two-dimensional analysis of high injection effects in AlGaAs/GaAs HBTs with semi-insulating external collectors
AU - Horio, Kazushige
AU - Oguchi, Akira
AU - Yanais, Hisayoshi
N1 - Funding Information:
Acknowledgements--aTuhteh orsa reg ratefutl o Y. Iwatsu p. 195( 1990). 1990I EEE Bipolar Circuitas nd TechnologyM eeting, for his assistance. Thwiso rkw ass upportebdy the Project 22. W. Shocideay ndW . T. Read,P hys.R ev. 878, 35( 1952). ResearchF unda t theS hibaurIan stitutoef Technologayn d 23. J. E. Sutherlanadn dJ . R. HauserI,E EE Trans.E lectron by the Saneyoshi ScholarsFhoipu ndation. DevicesE D-24,3 63( 1977). 24. H. C. CaseyJ r and M. B. Panish, Heterostructure Lasers.A cademiPcr ess, NewY ork (1978).
PY - 1991/12
Y1 - 1991/12
N2 - Two-dimensional simulations of AlGaAs/GaAs HBTs with various collector structures were performed. The introduction of a semi-insulating external collector improves cutoff frequency fT in the low current region because the base-collector capacitance decreases. However, it leads to an earlier fall of fT in the high current region, because a high injection effect is enhanced. This high injection effect has two features: (1) expansion of the collector depletion layer is remarkable near the interface between the intrinsic collector and the semi-insulating external collector, resulting in a longer transit time in this region; and (2) the effective channel in the intrinsic collector becomes narrow by introducing the semi-insulating external collector and so the effective current density there becomes high, leading to an earlier appearance of the high injection situation. It is shown that to minimize these unfavourable high injection effects, the semi-insulating layer should be slightly away from the intrinsic collector region so that it may not affect electron transport in the intrinsic collector region.
AB - Two-dimensional simulations of AlGaAs/GaAs HBTs with various collector structures were performed. The introduction of a semi-insulating external collector improves cutoff frequency fT in the low current region because the base-collector capacitance decreases. However, it leads to an earlier fall of fT in the high current region, because a high injection effect is enhanced. This high injection effect has two features: (1) expansion of the collector depletion layer is remarkable near the interface between the intrinsic collector and the semi-insulating external collector, resulting in a longer transit time in this region; and (2) the effective channel in the intrinsic collector becomes narrow by introducing the semi-insulating external collector and so the effective current density there becomes high, leading to an earlier appearance of the high injection situation. It is shown that to minimize these unfavourable high injection effects, the semi-insulating layer should be slightly away from the intrinsic collector region so that it may not affect electron transport in the intrinsic collector region.
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U2 - 10.1016/0038-1101(91)90035-W
DO - 10.1016/0038-1101(91)90035-W
M3 - Article
AN - SCOPUS:0026373402
SN - 0038-1101
VL - 34
SP - 1393
EP - 1400
JO - Solid-State Electronics
JF - Solid-State Electronics
IS - 12
ER -