Impacts of recessed gate and fluoride-based plasma treatment approaches toward normally-off AlGaN/GaN HEMT

Jun Woo Heo, Young Jin Kim, Hyun Seok Kim

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

We report two approaches to fabricating high performance normally-off AlGaN/GaN high-electron mobility transistors (HEMTs). The fabrication techniques employed were based on recessed-metalinsulator-semiconductor (MIS) gate and recessed fluoride-based plasma treatment. They were selectively applied to the area under the gate electrode to deplete the two-dimensional electron gas (2-DEG) density. We found that the recessed gate structure was effective in shifting the threshold voltage by controlling the etching depth of gate region to reduce the AlGaN layer thickness to less than 8 nm. Likewise, the CF4 plasma treatment effectively incorporated negatively charged fluorine ions into the thin AlGaN barrier so that the threshold voltage shifted to higher positive values. In addition to the increased threshold voltage, experimental results showed a maximum drain current and a maximum transconductance of 315 mA/mm and 100 mS/mm, respectively, for the recessed-MIS gate HEMT, and 340 mA/mm and 330 mS/mm, respectively, for the fluoride-based plasma treated HEMT.

Original languageEnglish
Pages (from-to)9436-9442
Number of pages7
JournalJournal of Nanoscience and Nanotechnology
Volume14
Issue number12
DOIs
StatePublished - 1 Dec 2014

Keywords

  • Field plate (FP)
  • GaN
  • High-electron mobility transistors (HEMTs)
  • Plasma treatment
  • Recessed gate
  • Threshold voltage

Fingerprint

Dive into the research topics of 'Impacts of recessed gate and fluoride-based plasma treatment approaches toward normally-off AlGaN/GaN HEMT'. Together they form a unique fingerprint.

Cite this