Yaddanapudi, Krishna and Saha, Sabyasachi and Raghavan, Srinivasan and Muraleedharan, K and Banerjee, Dipankar (2018) Nitridation of Sapphire as a Precursor to GaN Growth: Structure and Chemistry. Crystal Growth & Design, 18 (9). pp. 4978-4986. ISSN 1528-7483

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Abstract

Nitridation of sapphire substrates is used as a precursor to the growth of GaN films to provide a wetting layer which is closer in terms of structure and chemistry to the overlayer. Nitridation has been carried out by metal-organic chemical vapor deposition at 530, 800, and 1100 degrees C in an environment of NH3 and H-2. The structure and chemistry of the nitrided layer grown at these different temperatures have been studied by X-ray photoelectron spectroscopy, electron diffraction, high resolution electron microscopy, and electron energy loss spectroscopy. The low temperature nitridation process results in a nitrided layer in which oxygen has been partially replaced by nitrogen to form a cubic spinel-AL(x)O(y)N(z) structure. Nitridation at 800 degrees and 1100 degrees C results in complete substitution of oxygen atoms by nitrogen to form a cubic rock salt AIN structure. These structures are stable on thermal annealing at 1000 degrees C prior to epitaxial GaN growth.

Item Type: Article
Subjects: Engineering Materials
Divisions: Director´┐Żs Secretariat
Depositing User: Bidhan Chaudhuri
Date Deposited: 31 Oct 2018 12:21
Last Modified: 31 Oct 2018 12:21
URI: http://cgcri.csircentral.net/id/eprint/4414

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