Title :
Lightly doped emitter HBT for low-power circuits
Author :
Chang, C.E. ; Chen, P.F. ; Asbeck, P.M. ; Tran, L.T. ; Streit, D.C. ; Oki, A.K.
Author_Institution :
Dept. of Electr. Eng. & Comput. Eng., California Univ., San Diego, La Jolla, CA, USA
fDate :
11/1/1997 12:00:00 AM
Abstract :
We report an approach to reduce the base-emitter capacitance in AlGaAs-GaAs heterojunction bipolar transistors (HBT´s) by adding a lightly doped emitter (LDE) region together with appropriate planar (δ) doping region to a conventional base-emitter junction. This improves both the ft and β for low collector current density (Jc) operation while preserving the high peak ft at high Jc. When applied to a current mode logic 128/129 programmable prescaler, the LDE HBT results in a reduction in power dissipation and improved bandwidth without any circuit modifications
Keywords :
III-V semiconductors; aluminium compounds; bipolar MMIC; bipolar digital integrated circuits; bipolar logic circuits; current-mode logic; doping profiles; gallium arsenide; heterojunction bipolar transistors; microwave bipolar transistors; prescalers; δ doping region; AlGaAs-GaAs; CML programmable prescaler; TRW MMIC HBT process; base-emitter capacitance reduction; current mode logic; digital circuits; heterojunction bipolar transistors; lightly doped emitter HBT; low collector current density operation; low-power circuits; planar doping region; power dissipation; Capacitance; Current density; Digital circuits; Doping; Gallium arsenide; Heterojunction bipolar transistors; Logic circuits; Microwave devices; Power dissipation; Space technology;
Journal_Title :
Microwave and Guided Wave Letters, IEEE
