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Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers

Papamichail, Alexis ; Persson, Axel R. ; Ricther, Steffen ; Kuhne, Philipp ; Persson, Per O.A. ; Thorsell, Mattias ; Hjelmgren, Hans ; Rorsman, Niklas and Darakchieva, Vanya LU (2022) 2022 Compound Semiconductor Week, CSW 2022
Abstract

Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized.... (More)

Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized. Furthermore, the sheet resistance, carrier density and mobility in HEMT structures with different grading profiles are compared and discussed. The conventional (non-graded) structure revealed the highest electron mobility of ~2350 cm2/V.s, which is among the highest values reported.

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author
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organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
graded channel HEMTs, polarization doping, RF devices
host publication
2022 Compound Semiconductor Week, CSW 2022
publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
conference name
2022 Compound Semiconductor Week, CSW 2022
conference location
Ann Arbor, United States
conference dates
2022-06-01 - 2022-06-03
external identifiers
  • scopus:85142540487
ISBN
9781665453400
DOI
10.1109/CSW55288.2022.9930457
language
English
LU publication?
yes
id
6d2f6c7a-1370-4ec5-a951-1f5cc5d25969
date added to LUP
2022-12-21 16:04:18
date last changed
2023-11-21 14:28:16
@inproceedings{6d2f6c7a-1370-4ec5-a951-1f5cc5d25969,
  abstract     = {{<p>Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized. Furthermore, the sheet resistance, carrier density and mobility in HEMT structures with different grading profiles are compared and discussed. The conventional (non-graded) structure revealed the highest electron mobility of ~2350 cm2/V.s, which is among the highest values reported.</p>}},
  author       = {{Papamichail, Alexis and Persson, Axel R. and Ricther, Steffen and Kuhne, Philipp and Persson, Per O.A. and Thorsell, Mattias and Hjelmgren, Hans and Rorsman, Niklas and Darakchieva, Vanya}},
  booktitle    = {{2022 Compound Semiconductor Week, CSW 2022}},
  isbn         = {{9781665453400}},
  keywords     = {{graded channel HEMTs; polarization doping; RF devices}},
  language     = {{eng}},
  publisher    = {{IEEE - Institute of Electrical and Electronics Engineers Inc.}},
  title        = {{Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers}},
  url          = {{http://dx.doi.org/10.1109/CSW55288.2022.9930457}},
  doi          = {{10.1109/CSW55288.2022.9930457}},
  year         = {{2022}},
}