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

low resistance
electric contacts
Auger electron spectroscopy
Annealing
Auger spectroscopy
annealing
electron spectroscopy
Transmission electron microscopy
X ray diffraction
transmission electron microscopy
Scanning electron microscopy
scanning electron microscopy
Ohmic contacts
Contact resistance
barrier layers
contact resistance
diffraction
Nitrides
nitrides
x rays

ASJC Scopus subject areas

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

Cite this

Thermally stable and low-resistance W/Ti/Au contacts to n-type GaN. / Reddy, V. Rajagopal; Kim, Sang Ho; Hong, Hyun Gi; Yoon, Sang Won; Ahn, Jae Pyoung; Seong, Tae Yeon.

In: Journal of Materials Science: Materials in Electronics, Vol. 20, No. 1, 01.01.2009, p. 9-13.

Research output: Contribution to journalArticle

Reddy, V. Rajagopal ; Kim, Sang Ho ; Hong, Hyun Gi ; Yoon, Sang Won ; Ahn, Jae Pyoung ; Seong, Tae Yeon. / Thermally stable and low-resistance W/Ti/Au contacts to n-type GaN. In: Journal of Materials Science: Materials in Electronics. 2009 ; Vol. 20, No. 1. pp. 9-13.
@article{e48cd61bcc9e4c8a948dfc279e0a5fc8,
title = "Thermally stable and low-resistance W/Ti/Au contacts to n-type GaN",
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.",
author = "Reddy, {V. Rajagopal} and Kim, {Sang Ho} and Hong, {Hyun Gi} and Yoon, {Sang Won} and Ahn, {Jae Pyoung} and Seong, {Tae Yeon}",
year = "2009",
month = "1",
day = "1",
doi = "10.1007/s10854-008-9586-4",
language = "English",
volume = "20",
pages = "9--13",
journal = "Journal of Materials Science: Materials in Electronics",
issn = "0957-4522",
publisher = "Springer New York",
number = "1",

}

TY - JOUR

T1 - Thermally stable and low-resistance W/Ti/Au contacts to n-type GaN

AU - Reddy, V. Rajagopal

AU - Kim, Sang Ho

AU - Hong, Hyun Gi

AU - Yoon, Sang Won

AU - Ahn, Jae Pyoung

AU - Seong, Tae Yeon

PY - 2009/1/1

Y1 - 2009/1/1

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=58149132625&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=58149132625&partnerID=8YFLogxK

U2 - 10.1007/s10854-008-9586-4

DO - 10.1007/s10854-008-9586-4

M3 - Article

AN - SCOPUS:58149132625

VL - 20

SP - 9

EP - 13

JO - Journal of Materials Science: Materials in Electronics

JF - Journal of Materials Science: Materials in Electronics

SN - 0957-4522

IS - 1

ER -