High-power-density 0.25 μm gate-length AlGaN/GaN high-electron-mobility transistors on semi-insulating 6H-SiC substrates

J. W. Lee, V. Kumar, I. Adesida

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

AlGaN/GaN high-electron-mobility transistors (HEMTs) on 6H-SiC substrates with a 0.25 μm gate length and with different gate-drain spacings, L GD, ranging from 1 to 7 μm have been fabricated for optimization of output power and investigation of trapping effects. A typical device with LGD = 1 μm exhibited a maximum drain current density of 1400 mA/mm, a peak extrinsic transconductance (gm) of 322 mS/mm, a device unity-gain cut-off frequency (fT) of 40.3 GHz, and a maximum frequency of oscillation (fMAX) of 85.3 GHz. Examination of small-signal RF and pulsed current-voltage measurements revealed that RF dispersion is closely related to the gate-drain spacing dimensions, indicating that large gate-drain spacing without the control of RF dispersion can adversely affect output power performance. The results were confirmed using load-pull performance measurements with better power and efficiency obtained for devices with shorter gate-drain separation. For a device with LGD = 1 μm and a 0.25 μm gate-length, a state-of-the-art output power density of 6.7 W/mm at 18 GHz was obtained, which indicates the potential of GaN HEMTs achievable by control of RF current dispersion.

Original languageEnglish
Pages (from-to)13-17
Number of pages5
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
Volume45
Issue number1 A
DOIs
Publication statusPublished - Jan 10 2006
Externally publishedYes

Fingerprint

High electron mobility transistors
high electron mobility transistors
radiant flux density
Substrates
Drain current
Voltage measurement
spacing
Cutoff frequency
Transconductance
Electric current measurement
output
Current density
transconductance
electrical measurement
unity
cut-off
examination
trapping
current density
oscillations

Keywords

  • GaN HEMT
  • Pulsed measurements
  • RF dispersion
  • SiC, microwave power FETs

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

@article{e86b3cb414b949049c51507ea8c6b193,
title = "High-power-density 0.25 μm gate-length AlGaN/GaN high-electron-mobility transistors on semi-insulating 6H-SiC substrates",
abstract = "AlGaN/GaN high-electron-mobility transistors (HEMTs) on 6H-SiC substrates with a 0.25 μm gate length and with different gate-drain spacings, L GD, ranging from 1 to 7 μm have been fabricated for optimization of output power and investigation of trapping effects. A typical device with LGD = 1 μm exhibited a maximum drain current density of 1400 mA/mm, a peak extrinsic transconductance (gm) of 322 mS/mm, a device unity-gain cut-off frequency (fT) of 40.3 GHz, and a maximum frequency of oscillation (fMAX) of 85.3 GHz. Examination of small-signal RF and pulsed current-voltage measurements revealed that RF dispersion is closely related to the gate-drain spacing dimensions, indicating that large gate-drain spacing without the control of RF dispersion can adversely affect output power performance. The results were confirmed using load-pull performance measurements with better power and efficiency obtained for devices with shorter gate-drain separation. For a device with LGD = 1 μm and a 0.25 μm gate-length, a state-of-the-art output power density of 6.7 W/mm at 18 GHz was obtained, which indicates the potential of GaN HEMTs achievable by control of RF current dispersion.",
keywords = "GaN HEMT, Pulsed measurements, RF dispersion, SiC, microwave power FETs",
author = "Lee, {J. W.} and V. Kumar and I. Adesida",
year = "2006",
month = "1",
day = "10",
doi = "10.1143/JJAP.45.13",
language = "English",
volume = "45",
pages = "13--17",
journal = "Japanese Journal of Applied Physics",
issn = "0021-4922",
publisher = "Japan Society of Applied Physics",
number = "1 A",

}

TY - JOUR

T1 - High-power-density 0.25 μm gate-length AlGaN/GaN high-electron-mobility transistors on semi-insulating 6H-SiC substrates

AU - Lee, J. W.

AU - Kumar, V.

AU - Adesida, I.

PY - 2006/1/10

Y1 - 2006/1/10

N2 - AlGaN/GaN high-electron-mobility transistors (HEMTs) on 6H-SiC substrates with a 0.25 μm gate length and with different gate-drain spacings, L GD, ranging from 1 to 7 μm have been fabricated for optimization of output power and investigation of trapping effects. A typical device with LGD = 1 μm exhibited a maximum drain current density of 1400 mA/mm, a peak extrinsic transconductance (gm) of 322 mS/mm, a device unity-gain cut-off frequency (fT) of 40.3 GHz, and a maximum frequency of oscillation (fMAX) of 85.3 GHz. Examination of small-signal RF and pulsed current-voltage measurements revealed that RF dispersion is closely related to the gate-drain spacing dimensions, indicating that large gate-drain spacing without the control of RF dispersion can adversely affect output power performance. The results were confirmed using load-pull performance measurements with better power and efficiency obtained for devices with shorter gate-drain separation. For a device with LGD = 1 μm and a 0.25 μm gate-length, a state-of-the-art output power density of 6.7 W/mm at 18 GHz was obtained, which indicates the potential of GaN HEMTs achievable by control of RF current dispersion.

AB - AlGaN/GaN high-electron-mobility transistors (HEMTs) on 6H-SiC substrates with a 0.25 μm gate length and with different gate-drain spacings, L GD, ranging from 1 to 7 μm have been fabricated for optimization of output power and investigation of trapping effects. A typical device with LGD = 1 μm exhibited a maximum drain current density of 1400 mA/mm, a peak extrinsic transconductance (gm) of 322 mS/mm, a device unity-gain cut-off frequency (fT) of 40.3 GHz, and a maximum frequency of oscillation (fMAX) of 85.3 GHz. Examination of small-signal RF and pulsed current-voltage measurements revealed that RF dispersion is closely related to the gate-drain spacing dimensions, indicating that large gate-drain spacing without the control of RF dispersion can adversely affect output power performance. The results were confirmed using load-pull performance measurements with better power and efficiency obtained for devices with shorter gate-drain separation. For a device with LGD = 1 μm and a 0.25 μm gate-length, a state-of-the-art output power density of 6.7 W/mm at 18 GHz was obtained, which indicates the potential of GaN HEMTs achievable by control of RF current dispersion.

KW - GaN HEMT

KW - Pulsed measurements

KW - RF dispersion

KW - SiC, microwave power FETs

UR - http://www.scopus.com/inward/record.url?scp=31544479077&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=31544479077&partnerID=8YFLogxK

U2 - 10.1143/JJAP.45.13

DO - 10.1143/JJAP.45.13

M3 - Article

VL - 45

SP - 13

EP - 17

JO - Japanese Journal of Applied Physics

JF - Japanese Journal of Applied Physics

SN - 0021-4922

IS - 1 A

ER -