Title :
Bipolar transistor with graded band-gap base
Author :
Hayes, J.R. ; Capasso, Federico ; Gossard, Arthur C. ; Malik, R.J. ; Wiegmann, W.
Author_Institution :
Bell Laboratories, Murray Hill, USA
Abstract :
We report the first compositionally graded base bipolar transistor. The device grown by MBE incorporates a wide gap Al0.35Ga0.65As emitter (n = 2 × 1016/cm3 and a 0.4 ¿m thick p+ (= 2 × 1018/cm3)base graded from Al0.20Ga0.80As to GaAs. DC current gain of 35 with flat, nearly ideal, collector characteristics are observed. Incorporation of a graded gap base gives much faster base transit times due to the induced quasi-electric field for electrons, thus allowing a precious tradeoff against the base resistance.
Keywords :
III-V semiconductors; aluminium compounds; bipolar transistors; gallium arsenide; molecular beam epitaxial growth; p-n heterojunctions; semiconductor epitaxial layers; semiconductor growth; AlGaAs/GaAs heterojunction; DC current gain; III-V semiconductors; MBE; base transit times; bipolar transistor; collector characteristics; epitaxial layers; graded band-gap base; induced quasi-electric field; wide gap Al0.35Ga0.65As emitter;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19830281
