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

doi:10.1007/s10854-008-9586-4

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

Department of Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

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 language	English
Pages (from-to)	9-13
Number of pages	5
Journal	Journal of Materials Science: Materials in Electronics
Volume	20
Issue number	1
DOIs	https://doi.org/10.1007/s10854-008-9586-4
Publication status	Published - 2009

ASJC Scopus subject areas

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

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10.1007/s10854-008-9586-4

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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}",

note = "Funding Information: Acknowledgement This work was supported by the basic research programme of the Korea Science and Engineering Foundation (Grant no. R01-2006-000-10904-0).",

year = "2009",

doi = "10.1007/s10854-008-9586-4",

language = "English",

volume = "20",

pages = "9--13",

journal = "Journal of Materials Science: Materials in Electronics",

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publisher = "Springer New York",

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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

N1 - Funding Information: Acknowledgement This work was supported by the basic research programme of the Korea Science and Engineering Foundation (Grant no. R01-2006-000-10904-0).

PY - 2009

Y1 - 2009

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.

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DO - 10.1007/s10854-008-9586-4

M3 - Article

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SN - 0957-4522

VL - 20

SP - 9

EP - 13

JO - Journal of Materials Science: Materials in Electronics

JF - Journal of Materials Science: Materials in Electronics

IS - 1

ER -

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

Abstract

ASJC Scopus subject areas

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