Title :
Ultra-high f/sub max/ and f/sub T/ InP/InGaAs double-heterojunction bipolar transistors with step-graded InGaAsP collector
Author :
Yamahata, S. ; Kurishima, K. ; Nakajima, H. ; Kobayashi, T. ; Matsuoka, Y.
Author_Institution :
NTT LSI Labs., Kanagawa, Japan
Abstract :
The high-frequency performance of small scale InP/InGaAs DHBTs with InGaAsP in the collector that has a highly Zn-doped base was investigated using various emitter-widths and lengths as functions of collector current I/sub C/ and collector/emitter voltage V/sub CE/. Narrowing the emitter-width is significantly more effective for increasing f/sub max/ than shortening the emitter-lengths. A DHBT with a narrow 0.8-/spl mu/m emitter-metal has an ultra-high f/sub max/ of 267 GHz and f/sub T/ of 144 GHz at an I/sub C/ as low as 4 mA. This increase in f/sub max/ is attributed to the low product of the base resistance and reduced base/collector capacitance.
Keywords :
III-V semiconductors; gallium arsenide; heterojunction bipolar transistors; indium compounds; microwave bipolar transistors; millimetre wave bipolar transistors; 0.8 micron; 144 GHz; 267 GHz; 4 mA; DHBTs; InP-InGaAs-InGaAsP; base resistance; base/collector capacitance; collector current; collector/emitter voltage; current-gain cutoff frequency; double-heterojunction bipolar transistors; emitter lengths; emitter widths; high-frequency performance; maximum oscillation frequency; step-graded collector; Argon; Bipolar transistors; Capacitance; Electrodes; Epitaxial growth; Epitaxial layers; Gold; Indium gallium arsenide; Indium phosphide; Wet etching;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1994. Technical Digest 1994., 16th Annual
Conference_Location :
Phildelphia, PA, USA
Print_ISBN :
0-7803-1975-3
DOI :
10.1109/GAAS.1994.636999
