Interfacial reaction and surface morphology of Pd/Re contact schemes to p-type GaN

Reddy, V. R. and Ramesh, C. K. and Reddy, P. N. (2004) Interfacial reaction and surface morphology of Pd/Re contact schemes to p-type GaN. INDIAN JOURNAL OF PURE & APPLIED PHYSICS, 42 (5). pp. 361-365. ISSN 0975-1041

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The interfacial reactions between the Pd (20 nm) / Re (25 nm) contacts and p-GaN (1.13x10(17) cm(-3)) have been investigated using glancing angle XRD and Auger depth profiling. The samples are annealed at temperatures of 550 degreesC and 650 degreesC for 1 min in a nitrogen ambient. The I-V measurements show that the as-deposited sample is ohmic with a contact resistance of 1.4x10(-3) Omega cm(2). However, the annealing of the sample at 550 degreesC results in much better ohmic behaviour with a specific contact resistance of 8.7x10(-4) Omega cm(2). Further, increase in annealing temperature (650 degreesC) causes the degradation of the ohmic property. Based on AES and XRD results, the formation of Ga-Pd reaction phases results in the generation of Ga vacancies at the GaN surface region, which plays a role in reducing contact resistivity. The AFM results show that the surface morphology of the as-deposited contact is fairly smooth (with a rms roughness of 1.7 nm) and when annealed at 550 degreesC contact has become somewhat degraded with it root-mean-square roughness of 6.5 nm.

Item Type: Article
Uncontrolled Keywords: interfacial reaction; Pd/Re contacts; surface morphology; glancing angle XRD; Auger depth pioliling
Subjects: D Physical Science > Electronic
Divisions: PG Centre Hassan > Electronics
Depositing User: lpa venkatesh user
Date Deposited: 28 Aug 2019 12:18
Last Modified: 28 Aug 2019 12:18

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