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Characterization of Trapping Effects Related to Carbon Doping Level in AlGaN Back-Barriers for AlGaN/GaN HEMTs

Castillo, Ragnar Ferrand Drake Del ; Chen, Ding Yuan ; Chen, Jr Tai ; Thorsell, Mattias ; Darakchieva, Vanya LU and Rorsman, Niklas (2024) In IEEE Transactions on Electron Devices
Abstract
The impact of different carbon concentrations in the Al 0.06 Ga 0.94 N graded back-barrier and GaN buffer of high electron mobility transistors (HEMTs) is investigated. Four epi-wafers with different carbon concentrations, ranging from 1 × 10 17 to 5 × 10 17 cm −3 , were grown by metal organic chemical vapor deposition (MOCVD). HEMTs with 100 and 200 nm gate lengths were fabricated and characterized with dc, Pulsed-IV, drain current transient spectroscopy (DCTS), and large-signal measurements at 30 GHz. It is shown that the back-barrier effectively prevents buffer-related electron trapping. The highest C-doping provides the best 2DEG confinement, while lower carbon doping levels are beneficial for a high output power and efficiency.... (More)
The impact of different carbon concentrations in the Al 0.06 Ga 0.94 N graded back-barrier and GaN buffer of high electron mobility transistors (HEMTs) is investigated. Four epi-wafers with different carbon concentrations, ranging from 1 × 10 17 to 5 × 10 17 cm −3 , were grown by metal organic chemical vapor deposition (MOCVD). HEMTs with 100 and 200 nm gate lengths were fabricated and characterized with dc, Pulsed-IV, drain current transient spectroscopy (DCTS), and large-signal measurements at 30 GHz. It is shown that the back-barrier effectively prevents buffer-related electron trapping. The highest C-doping provides the best 2DEG confinement, while lower carbon doping levels are beneficial for a high output power and efficiency. A C-doping of 1 × 10 17 cm −3 offers the highest output power at maximum power added efficiency (PAE) (1.8 W/mm), whereas 3 × 10 17 cm −3 doping provides the highest PAE ( > 40%). The C-profiles acquired by using secondary ion mass spectroscopy (SIMS), in combination with DCTS, is used to explain the electron trapping effects. Traps associated with the C-doping in the back-barrier are identified and the bias ranges for the trap activation are discussed. The study shows the importance of considering the C-doping level in the back-barrier of microwave GaN HEMTs for power amplification and generation. (Less)
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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
in press
subject
keywords
AlGaN/GaN, Aluminum gallium nitride, back-barrier, dispersion, double heterostructure, Electrons, Epitaxial growth, HEMTs, high electron mobility transistors (HEMTs), Logic gates, MODFETs, short channel effect (SCE), Wide band gap semiconductors
in
IEEE Transactions on Electron Devices
pages
2 pages
publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
external identifiers
  • scopus:85192168603
ISSN
0018-9383
DOI
10.1109/TED.2024.3392177
language
English
LU publication?
yes
id
210b7968-e6b8-42bb-b01a-d10b21077303
date added to LUP
2024-05-16 12:49:53
date last changed
2024-05-17 07:57:53
@article{210b7968-e6b8-42bb-b01a-d10b21077303,
  abstract     = {{The impact of different carbon concentrations in the Al 0.06 Ga 0.94 N graded back-barrier and GaN buffer of high electron mobility transistors (HEMTs) is investigated. Four epi-wafers with different carbon concentrations, ranging from 1  ×  10 17  to 5  ×  10 17  cm −3 , were grown by metal organic chemical vapor deposition (MOCVD). HEMTs with 100 and 200 nm gate lengths were fabricated and characterized with dc, Pulsed-IV, drain current transient spectroscopy (DCTS), and large-signal measurements at 30 GHz. It is shown that the back-barrier effectively prevents buffer-related electron trapping. The highest C-doping provides the best 2DEG confinement, while lower carbon doping levels are beneficial for a high output power and efficiency. A C-doping of 1  ×  10 17  cm −3 offers the highest output power at maximum power added efficiency (PAE) (1.8 W/mm), whereas 3  ×  10 17  cm −3  doping provides the highest PAE ( > 40%). The C-profiles acquired by using secondary ion mass spectroscopy (SIMS), in combination with DCTS, is used to explain the electron trapping effects. Traps associated with the C-doping in the back-barrier are identified and the bias ranges for the trap activation are discussed. The study shows the importance of considering the C-doping level in the back-barrier of microwave GaN HEMTs for power amplification and generation.}},
  author       = {{Castillo, Ragnar Ferrand Drake Del and Chen, Ding Yuan and Chen, Jr Tai and Thorsell, Mattias and Darakchieva, Vanya and Rorsman, Niklas}},
  issn         = {{0018-9383}},
  keywords     = {{AlGaN/GaN; Aluminum gallium nitride; back-barrier; dispersion; double heterostructure; Electrons; Epitaxial growth; HEMTs; high electron mobility transistors (HEMTs); Logic gates; MODFETs; short channel effect (SCE); Wide band gap semiconductors}},
  language     = {{eng}},
  publisher    = {{IEEE - Institute of Electrical and Electronics Engineers Inc.}},
  series       = {{IEEE Transactions on Electron Devices}},
  title        = {{Characterization of Trapping Effects Related to Carbon Doping Level in AlGaN Back-Barriers for AlGaN/GaN HEMTs}},
  url          = {{http://dx.doi.org/10.1109/TED.2024.3392177}},
  doi          = {{10.1109/TED.2024.3392177}},
  year         = {{2024}},
}