Enhancement-mode high electron mobility transistors lattice-matched to InP substrates utilizing Ti/Pt/Au metallization

Jae Hyung Jang, Seiyon Kim, Ilesanmi Adesida

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Enhancement-mode high electron mobility transistors (EHEMTs) were fabricated on In0.52Al0.48As/In0.53Ga 0.47As heterostructures lattice-matched to InP substrates. Vertical scaling of device heterostructures was carried out to realize a positive threshold voltage with Ti/Pt/Au gates. Submicron EHEMTs utilizing Ti/R/Au were fabricated and their performances were compared with those of conventional EHEMTs with buried-Pt gates. DC I-V characteristics of both devices exhibited excellent pinch-off characteristics and very low output conductance. Output conductance measured for both devices showed that EHEMTs exhibit smaller kink effects than normal depletion-mode HEMTs (DHEMTs) due to the operating mode of EHEMTs with forward gate bias. EHEMTs with 0.18 μm Ti/Pt/Au gates exhibited a threshold voltage of 100 mV, peak transconductance of 810 mS/mm, and unity current-gain cut-off frequency (fT) of 150 GHz, while those with buried-Pt gates exhibited a threshold voltage of 300 mV, peak transconductance of 880 mS/mm, and unity current-gain cut-off frequency (fT) of 100 GHz. Studies on the thermal stabilities of the two types of gate metallization have been carried out. The Ti/Pt/Au gates exhibited better thermal stability than Pt/Ti/Pt/Au gates in terms of variation of threshold voltages and maximum transconductance values at elevated temperatures.

Original languageEnglish
Pages (from-to)3349-3354
Number of pages6
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
Volume45
Issue number4 B
DOIs
Publication statusPublished - Apr 25 2006
Externally publishedYes

Fingerprint

High electron mobility transistors
Metallizing
high electron mobility transistors
augmentation
Threshold voltage
Substrates
threshold voltage
Transconductance
transconductance
Cutoff frequency
Heterojunctions
Thermodynamic stability
unity
thermal stability
cut-off
Gates (transistor)
output
depletion
direct current
scaling

Keywords

  • EHEMTs
  • High electron mobility transistors
  • InGaAs
  • InP

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

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title = "Enhancement-mode high electron mobility transistors lattice-matched to InP substrates utilizing Ti/Pt/Au metallization",
abstract = "Enhancement-mode high electron mobility transistors (EHEMTs) were fabricated on In0.52Al0.48As/In0.53Ga 0.47As heterostructures lattice-matched to InP substrates. Vertical scaling of device heterostructures was carried out to realize a positive threshold voltage with Ti/Pt/Au gates. Submicron EHEMTs utilizing Ti/R/Au were fabricated and their performances were compared with those of conventional EHEMTs with buried-Pt gates. DC I-V characteristics of both devices exhibited excellent pinch-off characteristics and very low output conductance. Output conductance measured for both devices showed that EHEMTs exhibit smaller kink effects than normal depletion-mode HEMTs (DHEMTs) due to the operating mode of EHEMTs with forward gate bias. EHEMTs with 0.18 μm Ti/Pt/Au gates exhibited a threshold voltage of 100 mV, peak transconductance of 810 mS/mm, and unity current-gain cut-off frequency (fT) of 150 GHz, while those with buried-Pt gates exhibited a threshold voltage of 300 mV, peak transconductance of 880 mS/mm, and unity current-gain cut-off frequency (fT) of 100 GHz. Studies on the thermal stabilities of the two types of gate metallization have been carried out. The Ti/Pt/Au gates exhibited better thermal stability than Pt/Ti/Pt/Au gates in terms of variation of threshold voltages and maximum transconductance values at elevated temperatures.",
keywords = "EHEMTs, High electron mobility transistors, InGaAs, InP",
author = "Jang, {Jae Hyung} and Seiyon Kim and Ilesanmi Adesida",
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T1 - Enhancement-mode high electron mobility transistors lattice-matched to InP substrates utilizing Ti/Pt/Au metallization

AU - Jang, Jae Hyung

AU - Kim, Seiyon

AU - Adesida, Ilesanmi

PY - 2006/4/25

Y1 - 2006/4/25

N2 - Enhancement-mode high electron mobility transistors (EHEMTs) were fabricated on In0.52Al0.48As/In0.53Ga 0.47As heterostructures lattice-matched to InP substrates. Vertical scaling of device heterostructures was carried out to realize a positive threshold voltage with Ti/Pt/Au gates. Submicron EHEMTs utilizing Ti/R/Au were fabricated and their performances were compared with those of conventional EHEMTs with buried-Pt gates. DC I-V characteristics of both devices exhibited excellent pinch-off characteristics and very low output conductance. Output conductance measured for both devices showed that EHEMTs exhibit smaller kink effects than normal depletion-mode HEMTs (DHEMTs) due to the operating mode of EHEMTs with forward gate bias. EHEMTs with 0.18 μm Ti/Pt/Au gates exhibited a threshold voltage of 100 mV, peak transconductance of 810 mS/mm, and unity current-gain cut-off frequency (fT) of 150 GHz, while those with buried-Pt gates exhibited a threshold voltage of 300 mV, peak transconductance of 880 mS/mm, and unity current-gain cut-off frequency (fT) of 100 GHz. Studies on the thermal stabilities of the two types of gate metallization have been carried out. The Ti/Pt/Au gates exhibited better thermal stability than Pt/Ti/Pt/Au gates in terms of variation of threshold voltages and maximum transconductance values at elevated temperatures.

AB - Enhancement-mode high electron mobility transistors (EHEMTs) were fabricated on In0.52Al0.48As/In0.53Ga 0.47As heterostructures lattice-matched to InP substrates. Vertical scaling of device heterostructures was carried out to realize a positive threshold voltage with Ti/Pt/Au gates. Submicron EHEMTs utilizing Ti/R/Au were fabricated and their performances were compared with those of conventional EHEMTs with buried-Pt gates. DC I-V characteristics of both devices exhibited excellent pinch-off characteristics and very low output conductance. Output conductance measured for both devices showed that EHEMTs exhibit smaller kink effects than normal depletion-mode HEMTs (DHEMTs) due to the operating mode of EHEMTs with forward gate bias. EHEMTs with 0.18 μm Ti/Pt/Au gates exhibited a threshold voltage of 100 mV, peak transconductance of 810 mS/mm, and unity current-gain cut-off frequency (fT) of 150 GHz, while those with buried-Pt gates exhibited a threshold voltage of 300 mV, peak transconductance of 880 mS/mm, and unity current-gain cut-off frequency (fT) of 100 GHz. Studies on the thermal stabilities of the two types of gate metallization have been carried out. The Ti/Pt/Au gates exhibited better thermal stability than Pt/Ti/Pt/Au gates in terms of variation of threshold voltages and maximum transconductance values at elevated temperatures.

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