Composite HfO2/Al2O3-dielectric AlGaAs/InGaAs MOS-HEMTs by using RF sputtering/ozone water oxidation

Ching Sung Lee, Yu Hao Liao, Bo Yi Chou, Han Yin Liu, Wei Chou Hsu

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

Composite HfO2/Al2O3-dielectric In 0.2Ga0.8As/Al0.24Ga0.76As metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) by using RF sputtering/ozone water oxidization, respectively, are investigated. In comparison with a conventional Schottky-gate device on the same epitaxial structure, an Al2O3 liner was chemically formed for the present MOS-HEMT to improve interfacial quality and decrease gate leakages. Moreover, a high-k HfO2 layer was further deposited on the Al 2O3 liner to enhance the gate modulation capability. The present MOS-HEMT with the devised HfO2/Al2O3 dielectric stack has demonstrated excellent switching characteristics, including superior subthreshold slope (S.S.) of 70 mV/dec and high drain-source current (IDS) on-off ratio of up to 6 orders. Improved direct-current (DC), radio-frequency (RF), and high-temperature device performances of the present design are also comprehensively studied in this work.

Original languageEnglish
Pages (from-to)194-203
Number of pages10
JournalSuperlattices and Microstructures
Volume72
DOIs
Publication statusPublished - 2014 Aug

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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