Low-resistance nonalloyed Ti/Al ohmic contacts on N-face n-type GaN via an O2 plasma treatment

Su Jin Kim; Tae Yang Nam; Tae Geun Kim

doi:10.1109/LED.2010.2093556

Low-resistance nonalloyed Ti/Al ohmic contacts on N-face n-type GaN via an O₂ plasma treatment

Su Jin Kim, Tae Yang Nam, Tae Geun Kim

School of Electrical Engineering

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

20 Citations (Scopus)

Abstract

The authors report improved electrical properties of nonalloyed Ti/Al ohmic contact to N-face n-type GaN via oxygen (O2) plasma treatment. The contact resistivity of Ti (50 nm)/ Al (35 nm) electrodes is reduced significantly from 4.3 × 10^-1 Ω • cm² to 2.53 × 10^-5 Ω • cm² by applying O₂ plasma to the GaN surface before the Ti/Al deposition. In this process, Ti-N bonds are expected to form, while the Ga-N bonds are broken by the O2 plasma, which eventually increases the nitrogen vacancies as well as the Ti-N phases at the GaN surface. This suggestion has been verified by X-ray photoelectron spectroscopy and transmission electron microscopy analyses.

Original language	English
Article number	5667037
Pages (from-to)	149-151
Number of pages	3
Journal	IEEE Electron Device Letters
Volume	32
Issue number	2
DOIs	https://doi.org/10.1109/LED.2010.2093556
Publication status	Published - 2011 Feb

Keywords

GaN
N-face
ohmic contacts
oxygen plasma

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

Access to Document

10.1109/LED.2010.2093556

Cite this

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title = "Low-resistance nonalloyed Ti/Al ohmic contacts on N-face n-type GaN via an O2 plasma treatment",

abstract = "The authors report improved electrical properties of nonalloyed Ti/Al ohmic contact to N-face n-type GaN via oxygen (O2) plasma treatment. The contact resistivity of Ti (50 nm)/ Al (35 nm) electrodes is reduced significantly from 4.3 × 10-1 Ω • cm2 to 2.53 × 10-5 Ω • cm2 by applying O2 plasma to the GaN surface before the Ti/Al deposition. In this process, Ti-N bonds are expected to form, while the Ga-N bonds are broken by the O2 plasma, which eventually increases the nitrogen vacancies as well as the Ti-N phases at the GaN surface. This suggestion has been verified by X-ray photoelectron spectroscopy and transmission electron microscopy analyses.",

keywords = "GaN, N-face, ohmic contacts, oxygen plasma",

author = "Kim, {Su Jin} and Nam, {Tae Yang} and Kim, {Tae Geun}",

note = "Funding Information: Manuscript received October 11, 2010; revised November 2, 2010; accepted November 5, 2010. Date of publication December 13, 2010; date of current version January 26, 2011. This work was supported in part by the National Research Foundation Grant funded by the Korea government under Projects F01-2007-000-11760-0, KRF-2008-D00074, and K20901000002-09E0100-00210) and in part by the Ministry of Knowledge Economy through IT R&D program (Project 2009-F-022-01) and through the International Joint R&D program (Project 10030797). The review of this letter was arranged by Editor G. Meneghesso.",

year = "2011",

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doi = "10.1109/LED.2010.2093556",

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volume = "32",

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journal = "IEEE Electron Device Letters",

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AU - Nam, Tae Yang

AU - Kim, Tae Geun

N1 - Funding Information: Manuscript received October 11, 2010; revised November 2, 2010; accepted November 5, 2010. Date of publication December 13, 2010; date of current version January 26, 2011. This work was supported in part by the National Research Foundation Grant funded by the Korea government under Projects F01-2007-000-11760-0, KRF-2008-D00074, and K20901000002-09E0100-00210) and in part by the Ministry of Knowledge Economy through IT R&D program (Project 2009-F-022-01) and through the International Joint R&D program (Project 10030797). The review of this letter was arranged by Editor G. Meneghesso.

PY - 2011/2

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N2 - The authors report improved electrical properties of nonalloyed Ti/Al ohmic contact to N-face n-type GaN via oxygen (O2) plasma treatment. The contact resistivity of Ti (50 nm)/ Al (35 nm) electrodes is reduced significantly from 4.3 × 10-1 Ω • cm2 to 2.53 × 10-5 Ω • cm2 by applying O2 plasma to the GaN surface before the Ti/Al deposition. In this process, Ti-N bonds are expected to form, while the Ga-N bonds are broken by the O2 plasma, which eventually increases the nitrogen vacancies as well as the Ti-N phases at the GaN surface. This suggestion has been verified by X-ray photoelectron spectroscopy and transmission electron microscopy analyses.

AB - The authors report improved electrical properties of nonalloyed Ti/Al ohmic contact to N-face n-type GaN via oxygen (O2) plasma treatment. The contact resistivity of Ti (50 nm)/ Al (35 nm) electrodes is reduced significantly from 4.3 × 10-1 Ω • cm2 to 2.53 × 10-5 Ω • cm2 by applying O2 plasma to the GaN surface before the Ti/Al deposition. In this process, Ti-N bonds are expected to form, while the Ga-N bonds are broken by the O2 plasma, which eventually increases the nitrogen vacancies as well as the Ti-N phases at the GaN surface. This suggestion has been verified by X-ray photoelectron spectroscopy and transmission electron microscopy analyses.

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