Enhancement of base conductivity via the piezoelectric effect in AlGaN/GaNHBTs

Citation
Pm. Asbeck et al., Enhancement of base conductivity via the piezoelectric effect in AlGaN/GaNHBTs, SOL ST ELEC, 44(2), 2000, pp. 211-219
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Eletrical & Eletronics Engineeing
Journal title
SOLID-STATE ELECTRONICS
ISSN journal
0038-1101 → ACNP
Volume
44
Issue
2
Year of publication
2000
Pages
211 - 219
Database
ISI
SICI code
0038-1101(200002)44:2<211:EOBCVT>2.0.ZU;2-9
Abstract
Large polarization effects in nitride-based heterostructures provide opport unities for controllably introducing negative charge, equivalent to accepto r-doping, in AlGaN/GaN HBT structures. This paper reviews evidence for pola rization-based doping effects in nitride-based materials, and discusses pot ential applications of these effects for the improvement of p-contacts and p-type base conductivity. It is shown that in conventional HBTs grown with Ga-terminated faces in the emitter-up configuration, the polarization-induc ed charges detract from the acceptor doping of the base. In contrast, the p olarization effects add to effective doping in the base in structures that are grown and processed as collector-up devices, or in devices that are gro wn emitter-up and utilize the transferred substrate approach. (C) 2000 Publ ished by Elsevier Science Ltd. All rights reserved.