Thermally stable and low-resistance W/Ti/Au contacts to n-type GaN

V. Rajagopal Reddy, Sang Ho Kim, Hyun Gi Hong, Sang Won Yoon, Jae Pyoung Ahn, Tae Yeon Seong

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We report on the formation of thermally stable and low-resistance Ti/ Au-based ohmic contacts to n-type GaN (4.0 × 10 18 cm -3) by using a W barrier layer. It is shown that the electrical characteristic of the sample is considerably improved upon annealing at 900 °C for 1 min in a N 2 ambient. The contacts produce the specific contact resistance as low as 6.7 × 10 -6 Ω cm 2 after annealing. The Norde and current-voltage methods are used to determine the effective Schottky barrier heights (SBHs). It is shown that annealing results in a reduction in the SBHs as compared to that of the as-deposited sample. Auger electron spectroscopy (AES), scanning transmission electron microscopy (STEM) and X-ray diffraction (XRD) examinations show that nitride and gallide phases are formed at the contact/GaN interface. Based on the AES, STEM and XRD results, a possible ohmic formation mechanism is described and discussed.

Original languageEnglish
Pages (from-to)9-13
Number of pages5
JournalJournal of Materials Science: Materials in Electronics
Volume20
Issue number1
DOIs
Publication statusPublished - 2009 Jan 1

    Fingerprint

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this