Influence of initial surface reconstruction on nitridation of Al2O3 (0001) using low pressure ammonia
2007 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 101, no 1, 013519- p.Article in journal (Refereed) Published
The purpose of this study is to investigate the effect of initial surface reconstruction on the nitridation process of Al2O3 (0001). This was done by exposing differently reconstructed sapphire substrates at different temperatures to low pressure ammonia (NH3). Structural and chemical analysis were carried out using low-electron energy diffraction and x-ray photoelectron spectroscopy. The experiments revealed that using low pressure ammonia (P-NH3 < 1 X 10(-5) Torr), no nitridation takes place on (1x1) unreconstructed surfaces. However, when the unreconstructed surface starts to change to a (root 31 x root 31) R +/- 9 degrees reconstructed surface, with increasing substrate temperature, the nitridation becomes successful. When using the initially reconstructed surface, the nitridation is successful even from the lowest temperature used. These results suggest that the initial surface reconstruction has a major effect on the nitridation process. This kinetic behavior has not been reported before, with most nitridation studies mainly focusing on the effect of surface temperature on the resulting surface morphology, rather than the actual kinetics of the process itself.
Place, publisher, year, edition, pages
2007. Vol. 101, no 1, 013519- p.
molecular-beam epitaxy, sapphire nitridation, alpha-alumina, gan growth, xps, plasma, films, temperature, alpha-al2o3, substrate
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-16331DOI: 10.1063/1.2384807ISI: 000243585200039ScopusID: 2-s2.0-33846332036OAI: oai:DiVA.org:kth-16331DiVA: diva2:334373
QC 201005252010-08-052010-08-052010-12-10Bibliographically approved