Electron Transport in GaSb/InAs Hot Electron Transistor Grown by Metalorganic Chemical Vapor Deposition

Kenji FUNATO  Kenichi TAIRA  Fumihiko NAKAMURA  Hiroji KAWAI  

IEICE TRANSACTIONS on Electronics   Vol.E76-C   No.9   pp.1384-1391
Publication Date: 1993/09/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Heterostructure Electron Devices)
hot electron transistor (HET),  thermionic emission,  GaSb,  InAs,  

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GaSb/InAs hot electron transistors (HETs) composed of a type-II misaligned quantum well operate at room temperature. The collector current is well described by the thermionic emission from the emitter. In order to get insight of the electron transport in the HET, the base width was varied or the collector barrier was modulated. The emitter's barrier height for the thermionic emission decreases with decreasing base width. This is caused by the increase of the quantum confinement energy in the InAs base with decreasing base width. Among HETs with a GaSb collector, a GaInSb abrupt layer, or a GaInSb graded layer at the collector edge, the latter type has the largest collector current. This indicates that collector grading reduces not only the collector barrier height, but also the quantum mechanical reflection of electrons. Collector-graded HETs with a 5 nm-thick base show a current gain of 8. The sheet resistance of InAs base is one order of magnitude less than bulk InAs without doping. This reduction is partly due to the accumulation of electrons transferred from the GaSb valence band to the InAs conduction band.