Electrical and structural properties of Ti/W/Au ohmic contacts on n-type GaN

V. Rajagopal Reddy, Tae Yeon Seong

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The electrical and structural properties of Ti/W/Au ohmic contacts to moderately doped n-GaN (4.07 × 1018 cm-3) have been investigated. The as-deposited and annealing contacts at temperatures below 750°C exhibit non-linear behaviour. However, the contact showed ohmic behaviour after annealing at a temperature in excess of 850°C. Specific contact resistance as low as 8.4 × 10-6 Ω cm2 is obtained from the Ti(12 nm)/W(20 nm)/Au(50 nm) contact annealed at 900°C for 1 min in N2 ambient. It is observed that annealing results in a large reduction (by ∼160 meV) in the Schottky barrier height of the contacts, compared to the as-deposited one. The atomic force microscopy results showed that the surface morphology of the contact annealed at 900°C is fairly smooth with a RMS roughness of 3.8 nm. Based on the Auger electron spectroscopy and glancing angle x-ray diffraction results, possible explanations are given to describe the annealing temperature dependence of the specific contact resistance of the contacts.

Original languageEnglish
Pages (from-to)975-979
Number of pages5
JournalSemiconductor Science and Technology
Volume19
Issue number8
DOIs
Publication statusPublished - 2004 Aug 1
Externally publishedYes

Fingerprint

Ohmic contacts
Structural properties
electric contacts
Electric properties
electrical properties
Annealing
annealing
Contact resistance
contact resistance
Auger electron spectroscopy
Temperature
Auger spectroscopy
Surface morphology
electron spectroscopy
Atomic force microscopy
x ray diffraction
roughness
Diffraction
Surface roughness
atomic force microscopy

ASJC Scopus subject areas

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

Cite this

Electrical and structural properties of Ti/W/Au ohmic contacts on n-type GaN. / Reddy, V. Rajagopal; Seong, Tae Yeon.

In: Semiconductor Science and Technology, Vol. 19, No. 8, 01.08.2004, p. 975-979.

Research output: Contribution to journalArticle

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