DocumentCode :
69284
Title :
AlGaN/SiC Heterojunction Bipolar Transistors Featuring AlN/GaN Short-Period Superlattice Emitter
Author :
Miyake, Hirokazu ; Kimoto, Tatsuya ; Suda, Jun
Author_Institution :
Dept. of Electron. Sci. & Eng., Kyoto Univ., Kyoto, Japan
Volume :
60
Issue :
9
fYear :
2013
fDate :
Sept. 2013
Firstpage :
2768
Lastpage :
2775
Abstract :
Growth and electrical characterization of aluminum gallium nitride (AlGaN)/SiC heterojunction bipolar transistors (HBTs) featuring AlN/GaN short-period superlattice as a quasi-AlGaN emitter are presented. The AlN/GaN superlattice emitter was grown by molecular beam epitaxy on off-axis SiC, which showed adequate structural and electronic properties as the emitter of the HBTs. We investigated the impact of Al composition in the emitter on the transport characteristics and current gain of the HBTs. Using Al composition of over 0.5, we achieved type-I band alignment in AlGaN/SiC, and suppressed the tunneling current via interface traps, resulting in an improved current gain of up to 2.7. Toward further improvement of current gain, we also investigated the effect of n-SiC spacer between n-AlGaN and p-SiC and p-SiC base width. Using 200-nm-thick n-SiC spacer and 250-nm-thick p-SiC base layer, we achieved an improved current gain of 13 owing to the reduced interface and bulk recombination.
Keywords :
III-V semiconductors; aluminium compounds; gallium compounds; heterojunction bipolar transistors; interface states; molecular beam epitaxial growth; semiconductor superlattices; tunnelling; wide band gap semiconductors; AlGaN-SiC; AlN-GaN; HBT; current gain; electrical characterization; electronic properties; heterojunction bipolar transistors; interface traps; molecular beam epitaxy; short-period superlattice emitter; size 200 nm; size 250 nm; structural properties; transport characteristics; tunneling current; type-I band alignment; Aluminum gallium nitride; Gallium nitride; Heterojunctions; III-V semiconductor materials; Silicon carbide; Superlattices; Surface morphology; Aluminum gallium nitride (AlGaN); band offset; current gain; heterojunction bipolar transistor (HBT); molecular beam epitaxy (MBE); silicon carbide (SiC); superlattice;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2013.2273499
Filename :
6574301
Link To Document :
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