Title :
Transient and steady-state Monte-Carlo simulation of the effects of junction grading on carrier transport in InAlAs/InGaAs HBTs
Author :
Hu, J. ; Pavlidis, D. ; Tomizawa, K.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
Abstract :
Various Al composition gradings (x/sub 0/) at the emitter/base junction of an InAlAs/InGaAs HBT (heterojunction bipolar transistor) are considered and their effects on carrier transport are studied using a self-consistent Monte Carlo technique. Electron transit time, velocity, and energy distribution are examined for this purpose. The shortest base-collector transit time (1.34 ps) and the highest average velocity (3.1*10/sup 7/ cm/s) are found for a design with intermediate grading (x/sub 0/=0.5 approximately 0.6). The study of the transient collector current and cutoff frequency characteristics shows similar results, i.e. improved device speed and frequency of operation with intermediate grading E/B junctions.<>
Keywords :
III-V semiconductors; Monte Carlo methods; aluminium compounds; carrier mobility; gallium arsenide; heterojunction bipolar transistors; indium compounds; semiconductor device models; simulation; transient response; Al composition gradings; HBT; InAlAs-InGaAs; Monte-Carlo simulation; base-collector transit time; carrier transport; cutoff frequency characteristics; electron transit time; electron velocity; emitter/base junction; energy distribution; heterojunction bipolar transistor; junction grading; self-consistent Monte Carlo technique; steady state simulation; transient collector current; transient simulation; Cutoff frequency; Electrons; Heterojunction bipolar transistors; Indium compounds; Indium gallium arsenide; Monte Carlo methods; Steady-state;
Conference_Titel :
Electron Devices Meeting, 1990. IEDM '90. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
DOI :
10.1109/IEDM.1990.237073
