A Thermally Stable NiZn/Ta/Ni Scheme to Replace AuBe/Au Contacts in High-Efficiency AlGaInP-Based Light-Emitting Diodes

Dae Hyun Kim, Jae Seong Park, Daesung Kang, Tae Yeon Seong

Research output: Contribution to journalArticle

Abstract

We developed NiZn/(Ta/)Ni ohmic contacts to replace expensive AuBe/Au contacts commonly used in high-efficiency AlGaInP-based light-emitting diodes (LEDs), and compared the electrical properties of the two contact types. Unlike the AuBe/Au (130 nm/100 nm) contact, the NiZn/Ta/Ni (130 nm/20 nm/100 nm) contact shows improved electrical properties after being annealed at 500°C, with a contact resistivity of 5.2 × 10−6 Ω cm2. LEDs with the NiZn/Ta/Ni contact exhibited a 4.4% higher output power (at 250 mW) than LEDs with the AuBe/Au contact. In contrast to the trend for the AuBe/Au contact, the Ga 2p core level for the NiZn/Ta/Ni contact shifted toward lower binding energies after being annealed at 500°C. Auger electron spectroscopy (AES) depth profiles showed that annealing the AuBe/Au samples caused the outdiffusion of both Be and P atoms into the metal contact, whereas in the NiZn/Ta/Ni samples, Zn atoms indiffused into the GaP layer. The annealing-induced electrical degradation and ohmic contact formation mechanisms are described and discussed on the basis of the results of x-ray photoemission spectroscopy and AES.

Original languageEnglish
Pages (from-to)1-5
Number of pages5
JournalJournal of Electronic Materials
DOIs
Publication statusAccepted/In press - 2017 Mar 8

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Keywords

  • AlGaInP
  • light-emitting diode
  • NiZn solid solution
  • Ohmic contact
  • x-ray photoemission spectroscopy

ASJC Scopus subject areas

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

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