TY - JOUR
T1 - Functional heterostructure-emitter bipolar transistor (HEBT) with graded-confinement and pseudomorphic-base structure
AU - Tsai, Jung Hui
AU - Cheng, Shiou Ying
AU - Shih, Hui Jung
AU - Liu, Wen Chau
N1 - Funding Information:
Acknowledgements—Part of this work was supported by the National Science Council of the Republic of China under Contract No. NSC 86-2215-E-006-005.
PY - 1998/9
Y1 - 1998/9
N2 - In this paper, a new functional heterostructure-emitter bipolar transistor (HEBT) with a graded AlxGa1-xAs confinement layer and a pseudomorphic InGaAs/GaAs base structure is fabricated and demonstrated. Due to the insertion of an InGaAs quantum well (QW) between the emitter-base (E-B) junction, the valence band discontinuity can be enhanced and a high emitter injection efficiency may be achieved. Furthermore, the potential spike of the graded AlxGa1-xAs/GaAs heterojunction is expected to be smoothed out which results in a lower offset voltage. The excellent transistor characteristics include a high current gain of 120 and a low offset voltage of 100 mV. In addition, an interesting S-shaped multiple negative differential resistance (MNDR) phenomenon is observed in the inverted operation mode. This may be attributed to an avalanche multiplication and a sequential two-stage barrier lowering effect resulting from the accumulation of holes at the base and electrons at the InGaAs QW, respectively. Consequently, owing to the remarkable transistor performance and MNDR characteristics, the studied HEBT shows good promise for applications in amplifiers and multiple-valued logic circuits.
AB - In this paper, a new functional heterostructure-emitter bipolar transistor (HEBT) with a graded AlxGa1-xAs confinement layer and a pseudomorphic InGaAs/GaAs base structure is fabricated and demonstrated. Due to the insertion of an InGaAs quantum well (QW) between the emitter-base (E-B) junction, the valence band discontinuity can be enhanced and a high emitter injection efficiency may be achieved. Furthermore, the potential spike of the graded AlxGa1-xAs/GaAs heterojunction is expected to be smoothed out which results in a lower offset voltage. The excellent transistor characteristics include a high current gain of 120 and a low offset voltage of 100 mV. In addition, an interesting S-shaped multiple negative differential resistance (MNDR) phenomenon is observed in the inverted operation mode. This may be attributed to an avalanche multiplication and a sequential two-stage barrier lowering effect resulting from the accumulation of holes at the base and electrons at the InGaAs QW, respectively. Consequently, owing to the remarkable transistor performance and MNDR characteristics, the studied HEBT shows good promise for applications in amplifiers and multiple-valued logic circuits.
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U2 - 10.1006/spmi.1996.0451
DO - 10.1006/spmi.1996.0451
M3 - Article
AN - SCOPUS:0031621030
SN - 0749-6036
VL - 24
SP - 189
EP - 195
JO - Superlattices and Microstructures
JF - Superlattices and Microstructures
IS - 3
ER -