Title :
AlGaAs/GaAs P-n-p HBTs with high maximum frequency of oscillation
Author :
Sullivan, G.J. ; Chang, M.F. ; Sheng, Neng-Haung ; Anderson, R.J. ; Wang, Nan-Lei ; Wang, Keh-Chung ; Higgins, John A. ; Asbeck, Peter M.
Author_Institution :
Rockwell Int. Sci. Center, Thousand Oaks, CA, USA
Abstract :
An investigation of P-n-p HBTs (heterojunction bipolar transistors) with an f/sub max/ of 39 GHz and an f/sub t/ of 19 GHz is presented. Power-added efficiency of 31% was obtained in an amplifier at 10 GHz. The design of the high-speed AlGaAs/GaAs P-n-p HBTs takes account of the large degeneracy in the heavily n-type GaAs base. This doping-dependent degeneracy can induce gradients in the valence-band edge to improve the base transit time. High injection efficiency can be maintained in spite of the large degeneracy by increasing the aluminum content of the emitter. HBTs with emitter aluminum contents of 40% and 75% are described.<>
Keywords :
III-V semiconductors; aluminium compounds; degenerate semiconductors; gallium arsenide; heterojunction bipolar transistors; semiconductor device testing; solid-state microwave devices; 10 GHz; 19 GHz; 31 percent; 39 GHz; AlGaAs-GaAs; P-n-p HBTs; amplifier; base transit time; doping-dependent degeneracy; injection efficiency; large degeneracy; maximum frequency of oscillation; microwave power gain; pnp junctions; power added efficiency; valence-band edge; Aluminum; Charge carrier processes; Doping; Fabrication; Frequency; Gallium arsenide; Heterojunction bipolar transistors; Photonic band gap; Power amplifiers; Tail;
Journal_Title :
Electron Device Letters, IEEE
