p-InGaN/n-GaN Heterojunction Diodes and their Application to Heterojunction Bipolar Transistors
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Published:2000
Issue:
Volume:639
Page:
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ISSN:0272-9172
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Container-title:MRS Proceedings
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language:en
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Short-container-title:MRS Proc.
Author:
Makimoto Toshiki,Kumakura Kazuhide,Nishida Toshio,Kobayashi Naoki
Abstract
ABSTRACTp-InGaN/n-GaN heterojunction diodes were grown by metalorganic vapor phase epitaxy and characterized using current-voltage (I-V) and capacitance-voltage (C-V) measurements. We changed the In mole fraction in p-InGaN from 0 to 25% to investigate diode characteristics. All the diodes showed rectified I-V characteristics at room temperature. The ideality factors obtained from forward I-V characteristics were around 2, meaning that the recombination current is dominant instead of the tunneling current through the defects in depletion layers of the diodes. The breakdown voltage in reverse I-V characteristics depends on the net donor concentration (ND - NA) in n-GaN instead of the In mole fraction in p-InGaN. This result also means that the defects in p-InGaN do not influence the breakdown voltage. The built-in potential from C-V measurements decreases with the In mole fraction in p-InGaN, meaning that the valence band discontinuity increases with the In mole fraction. This valence band discontinuity realizes the hole confinement in an HBT with an p-InGaN base. Using these InGaN/GaN heterojunction diodes, an InGaN/GaN double heterojunction bipolar transistor was fabricated for the first time. The maximum current gain of 1.2 was obtained at room temperature.
Publisher
Springer Science and Business Media LLC
Subject
General Engineering