High-quality nanodisk of InGaN/GaN MQWs fabricated by neutral-beam-etching and GaN regrowth: Towards directional micro-LED in top-down structure

Kexiong Zhang, Tokio Takahashi, Daisuke Ohori, Guangwei Cong, Kazuhiko Endo, Naoto Kumagai, Seiji Samukawa, Mitsuaki Shimizu, Xuelun Wang

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

A nanodisk array of blue InGaN/GaN multiple quantum wells was made using neutral beam etching (NBE) followed by GaN regrowth. The NBE-fabricated nanodisk presented a vertical and highly smooth sidewall surface where the InGaN well layers were easily distinguished even with a scanning electron microscope. A high interface quality without any voids or obvious defects was obtained between the nanodisk and the regrown-GaN layer. The nanodisk after regrowth presented a smaller blueshift of photoluminescence emission energy (12 meV) and a substantially higher and almost constant internal quantum efficiency of ∼50% over three orders of magnitude of excitation laser power when compared to the nanodisk before regrowth. This study shows that the process of NBE nanodisk etching followed by GaN regrowth represents a promising step forward in the development of truncated cone-shaped directional micro-LEDs with a buried active region in a top-down structure.

Original languageEnglish
Article number075001
JournalSemiconductor Science and Technology
Volume35
Issue number7
DOIs
Publication statusPublished - 2020 Jul

Keywords

  • InGaN/GaN multiple quantum wells
  • directional micro-LED
  • nanodisk
  • neutral beam etching
  • regrowth

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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