Title :
A New InP/InGaAs Double Heterojunction Bipolar Transistor With a Step-Graded InAlGaAs Collector Structure
Author :
Chen, Tzu-Pin ; Cheng, Shiou-Ying ; Hung, Ching-Wen ; Chu, Kuei-Yi ; Chen, Li-Yang ; Tsai, Tsung-Han ; Liu, Wen-Chau
Author_Institution :
Nat. Cheng-Kung Univ., Tainan
Abstract :
An interesting InP/InGaAs double heterojunction bipolar transistor with a step-graded InAlGaAs layer at the base-collector (B-C) heterojunction is fabricated and studied. Simulated results reveal that the potential spike at the B-C heterointerface is completely eliminated. Experimentally, the operation regime is wider than 11 decades in magnitude of the collector current (Ic = 10-12 A to Ic = 10-1 A). Furthermore, the studied device exhibits a relatively high common-emitter breakdown voltage and low output conductance even at high temperature. In the microwave characteristics, the unity current gain cutoff frequency fT = 72.7 GHz and the maximum oscillation frequency f max = 50 GHz are achieved for a nonoptimized device (AE = 6 times 6 mum2).
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; heterojunction bipolar transistors; indium compounds; millimetre wave bipolar transistors; semiconductor device breakdown; InAlGaAs; InP-InGaAs; base-collector heterojunction; common-emitter breakdown voltage; double heterojunction bipolar transistor; frequency 50 GHz; frequency 72.7 GHz; low output conductance; maximum oscillation frequency; microwave characteristics; step-graded collector structure; unity current gain cutoff frequency; Bipolar transistors; Breakdown voltage; Cutoff frequency; Double heterojunction bipolar transistors; Electric breakdown; Indium gallium arsenide; Indium phosphide; Microwave devices; Optical materials; Photonic band gap; Breakdown; electron blocking; potential spike; step-graded collector;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2007.911286
