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Transmission electron microscopy study of the nitridation of the (0001) sapphire surface

1999; American Institute of Physics; Volume: 75; Issue: 26 Linguagem: Inglês

10.1063/1.125554

1520-8842

P. Vennéguès, B. Beaumont,

ZnO doping and properties

The purpose of this letter is to study, using transmission electron microscopy, the nitridation of the (0001) sapphire surface which is a key step for the fabrication of high-quality GaN materials. A nitridation conducted at 1080 °C during 7 min at atmospheric pressure with a 2 slm NH3 flow, results in the formation of a fully crystalline 10-atomic-planes-thick AlN film by the chemical transformation of the Al2O3 surface. From measurements of interplanar distances in high-resolution images, we show that this chemical transformation is incomplete, i.e., that a few Al vacancies and/or O atoms remain in the AlN structure.