Formation of thermally stable low-resistance Ti/W/Au ohmic contacts on n-type GaN

Reddy, V. R. and Kim, S. H. and Seong, T. Y. (2005) Formation of thermally stable low-resistance Ti/W/Au ohmic contacts on n-type GaN. Applied Physics A-Materials Science & Processing, 81 (3). pp. 561-567. ISSN 1432-0630

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Official URL: https://doi.org/10.1007/s00339-004-2673-3

Abstract

A Ti(12 nm)W(20 nm)Au(50 nm) metallization scheme has been investigated for obtaining thermally stable low-resistance ohmic contacts to n-type GaN (4.0×1018 cm-3). It is shown that the current–voltage (I–V) characteristics of the samples are abnormally dependent on the annealing temperature. For example, the samples that were annealed at temperatures below 750 °C for 1 min in a N2 ambient show rectifying behavior. However, annealing the samples at temperatures in excess of 850 °C results in linear I–V characteristics. The contact produces a specific contact resistance as low as 8.4×10-6 Ω cm2 when annealed at 900 °C. It is further shown that the contacts are fairly thermally stable even after annealing at 900 °C; annealing the samples at 900 °C for 30 min causes insignificant degradation of the electrical and structural properties. Based on glancing angle X-ray diffraction and Auger electron microscopy results, the abnormal temperature dependence of the ohmic behavior is described and discussed.

Item Type: Article
Subjects: D Physical Science > Electronic
Divisions: PG Centre Hassan > Electronics
Depositing User: manjula User
Date Deposited: 05 Sep 2019 07:48
Last Modified: 05 Sep 2019 07:48
URI: http://eprints.uni-mysore.ac.in/id/eprint/7626

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