High-performance GaN-based light emitting diodes grown on 8-inch Si substrate by using a combined low-temperature and high-temperature-grown AlN buffer layer

Jeong Tak Oh, Yong Tae Moon, Jung Hun Jang, Jung Hyun Eum, Youn Joon Sung, Sang Youl Lee, Jun O. Song, Tae Yeon Seong

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

A combined buffer layer growth process was developed to grow crack-free GaN layers on 8-inch Si(111) wafers and so light-emitting diodes (LEDs). The combined buffer layer consisted of 2 nm-thick low-temperature (LT, 850 °C)-AlN, 8 nm-thick graded-temperature AlN, and 200 nm-thick high-temperature (HT, 1100 °C)-AlN layers. The X-ray diffraction (XRD) results showed that the LT-HT-AlN buffer layer exhibited better crystal quality than the HT-AlN buffer layer. The atomic force microscopy (AFM) images revealed that compared to the LT-HT-AlN buffer layer, the HT-AlN buffer layer had a rough surface with numerous bright spots, which correspond to N-polar AlN hillocks. Scanning electron microscopy (SEM) results showed many pits in the HT-AlN buffer layer. Transmission electron microscopy (TEM) results showed that the HT-AlN buffer layer contained about 1.3 nm-thick amorphous SixNy layer at the interface, while the LT-HT-AlN buffer layer showed a relatively smooth interface. It was further shown that using the LT-HT-AlN buffer layer, high-quality crack-free n-GaN layers (2.5 μm-thick) were grown on the 8-inch Si(111) substrate, which was confirmed by the XRD and cathodoluminescence results. Subsequently, packaged vertical LEDs (chip size: 1400 × 1400 μm2) grown on the LT-HT-AlN buffer layers showed higher light output power and chip yield than LEDs with the HT-AlN buffer layer.

Original languageEnglish
Pages (from-to)630-636
Number of pages7
JournalJournal of Alloys and Compounds
Volume732
DOIs
Publication statusPublished - 2018 Jan 25

Keywords

  • AlN buffer
  • Electron microscopy
  • GaN
  • Light emitting diode
  • Si substrate

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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