Title :
Experimental comparison of base recombination currents in abrupt and graded AlGaAs/GaAs heterojunction bipolar transistors
Author_Institution :
Solid State Lab., Stanford Univ., CA, USA
Abstract :
The relative importance of the base bulk recombination current and the base-emitter junction space charge recombination current is examined for AlGaAs/GaAs HBTs with different grading schemes in the base-emitter junction. Experimental results demonstrate that, in abrupt HBTs, the base bulk recombination current is larger, and the base current increases with the base-emitter bias with an ideality factor of approximately 1. In contrast, in graded HBTs, the space charge recombination current dominates and the base current ideality factor is approximately 2. These experimental results agree well with a published theoretical calculation.
Keywords :
III-V semiconductors; aluminium compounds; electron-hole recombination; gallium arsenide; heterojunction bipolar transistors; space charge; abrupt HBTs; base recombination currents; base-emitter junction; graded HBTs; heterojunction bipolar transistors; space charge recombination current;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19911310
