Title :
High-gain InGaAlAs/InGaAs heterojunction bipolar transistors and phototransistors
Author :
Dodabalapur, Ananth ; Chang, Tao-yuan
Author_Institution :
AT&T Bell Labs., Holmdel, NJ, USA
Abstract :
The characteristics of InGaAlAs/InGaAs heterojunction bipolar transistors (HBTs) grown by molecular beam epitaxy are described. A current gain of 15600 at a current density of approximately 10/sup 4/ A/cm/sup 2/ and an emitter-base heterojunction ideality factor of 1.02 were measured. Appropriately designed InGaAlAs/InGaAs HBTs, when operated as phototransistors, also had high gains. A current gain of 1000 for a collector current of only 10 mu A was obtained for phototransistors. Such high gains are due to low recombination currents as a consequence of the good crystalline quality of the InGaAlAs bulk and InGaAlAs/InGaAs interface.<>
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; heterojunction bipolar transistors; indium compounds; molecular beam epitaxial growth; phototransistors; semiconductor epitaxial layers; 10 muA; HBTs; InGaAlAs-InGaAs; characteristics; collector current; crystalline quality; current density; current gain; emitter-base heterojunction ideality factor; heterojunction bipolar transistors; high gains; low recombination currents; molecular beam epitaxy; phototransistors; semiconductors; Bipolar transistors; Current density; Current measurement; Density measurement; Gain measurement; Heterojunction bipolar transistors; Indium gallium arsenide; Indium phosphide; Molecular beam epitaxial growth; Phototransistors;
Journal_Title :
Electron Device Letters, IEEE
