High temperature annealing of AlGaN: Stress and composition changes

A. Sarua, S. Rajasingam, M. Kuball, C. Younes, B. Yavich, Wang N Wang

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1 Citation (Scopus)

Abstract

Atomic force microscopy, micro-Raman scattering and Auger spectroscopy were applied to study stress and material composition in AlGa N grown by MOCHA on sapphire. Samples were annealed in N , O and air ambient between 800 °C and 1200 °C. Annealing at temperatures above 800 °C led to composition changes, cracks and defect formation resulting in stress release. Additionally, a change of built-in stress from tensile to compressive was observed after air annealing. Auger spectroscopy analysis showed this switching of stress to be related to oxygen incorporation. Oxygen accumulates in areas of macroscopic cracks as well as microscopic defects. Oxygen diffusion in AlGaN was found to be largely enhanced in the presence of water vapor in oxygen ambient. Samples were thermally stable up to 1100 °C in nitrogen and oxygen. Annealing in air led to a large surface oxidation.
Original languageEnglish
Pages (from-to)568-571
Number of pages4
JournalPhysica Status Solidi (C)
Volume0
Issue number1
Early online date19 Dec 2002
DOIs
Publication statusPublished - Dec 2002
Event2nd International Workshop on Nitride Semiconductors, IWN 2002 - Aachen, Germany
Duration: 22 Jul 200225 Jul 2002

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