Title :
Comparison of In/sub 0.5/Ga/sub 0.5/P/GaAs single- and double-heterojunction bipolar transistors with a carbon-doped base
Author :
Hanson, A.W. ; Stockman, S.A. ; Stillman, G.E.
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA
Abstract :
A comparison of MOCVD-grown, n-p-n In/sub 0.5/Ga/sub 0.5/P/GaAs single- and double-heterojunction bipolar transistors (SHBTs and DHBTs) with a carbon-doped base is presented. A base doping level of 2.5*10/sup 19/ cm/sup -3/ was employed in both device structures, resulting in a base sheet resistance of 500 Omega /sq. Common-emitter current gains as high as 210 and 150 were measured for the SHBTs and DHBTs, respectively. Results of a DC performance optimization study indicate that a 15- and 25-AA undoped set-back layer at the emitter-base junction provides optimal common-emitter current gain. The DHBTs exhibited a 40% improvement in common-base breakdown voltage compared to SHBTs (25 versus 18 V), indicating that In/sub 0.5/Ga/sub 0.5/P/GaAs DHBTs may prove suitable for power device applications.<>
Keywords :
III-V semiconductors; carbon; gallium arsenide; gallium compounds; heterojunction bipolar transistors; indium compounds; semiconductor doping; semiconductor growth; vapour phase epitaxial growth; 15 A; 18 V; 25 A; 25 V; DC performance optimization study; DHBTs; In/sub 0.5/Ga/sub 0.5/P:C; InGaP-GaAs; SHBTs; base doping level; base sheet resistance; common emitter current gains; common-base breakdown voltage; common-emitter current gain; double-heterojunction bipolar transistors; emitter-base junction; n-p-n transistors; power device applications; semiconductors; set-back layer; single-heterojunction bipolar transistor; Bipolar transistors; Current measurement; Doping profiles; Dry etching; Electrons; Gallium arsenide; Heterojunction bipolar transistors; MOCVD; Semiconductor materials; Wet etching;
Journal_Title :
Electron Device Letters, IEEE
