Enhanced thermal stability of Ag ohmic reflector for InGaN/GaN light-emitting diode using a Ru capping layer

Jae Seong Park, Joon Woo Jeon, Chang Hyung Lee, Chang Hoon Choi, Sungho Jin, Tae Yeon Seong

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

A Ru capping layer is employed to improve the thermal stability of Ag ohmic reflectors for high-power GaN-based light-emitting diodes (LEDs). The 20-nm-thick Ru capping layer is shown to be fairly effective in suppressing agglomeration by forming RuO 2. The Ag/Ru contacts exhibit specific contact resistance of 8.1 × 10 -5 Ω cm 2 and reflectance of ∼89% at a wavelength of 450 nm when annealed at 500°C for 1 min, which are much better than that of Ag only contacts. Blue LEDs fabricated with the 500°C-annealed Ag/Ru contacts give a forward voltage of 2.98 V at an injection current of 20 mA, which is lower than that (3.02 V) of LEDs with the 500°C-annealed Ag only contacts. LEDs with the 500°C-annealed Ag/Ru contacts show 25% higher output power (at 20 mA) than LEDs with the 500°C-annealed Ag only contacts. X-ray photoemission spectroscopy examinations are performed to describe the improved electrical performance of the Ag/Ru contacts.

Original languageEnglish
Pages (from-to)357-363
Number of pages7
JournalSuperlattices and Microstructures
Volume52
Issue number3
DOIs
Publication statusPublished - 2012 Sep

Keywords

  • A Ru capping layer
  • Ag ohmic reflector
  • GaN
  • Light-emitting diode

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Enhanced thermal stability of Ag ohmic reflector for InGaN/GaN light-emitting diode using a Ru capping layer'. Together they form a unique fingerprint.

Cite this