Structural properties of epitaxial gamma-Al2O3(111) thin films on 4H-SiC(0001)
2007 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 90, no 6, 061916- p.Article in journal (Refereed) Published
Al2 O3 thin films were grown on 4H-SiC (0001) by thermal atomic layer deposition and were crystallized to the γ- Al2 O3 phase by rapid thermal annealing in N2 at 1100 °C. The films were found to be chemically stable during processing based on x-ray photoelectron spectroscopy. The change in film structure was initially confirmed by reflection high-energy electron diffraction. As shown by high-resolution transmission electron microscopy images, the abrupt interface of the as-deposited films with the 4H-SiC substrate was preserved during crystallization, indicating no interfacial reaction. Selected area electron diffraction and synchrotron-based x-ray diffraction established an epitaxial relationship of γ- Al2 O3 (111) ∥ 4H-SiC (0001) and in-plane orientation of γ- Al2 O3 (1 1- 0) ∥ 4H-SiC (11 2- 0). No other alumina phases or orientations were observed and no in-plane misorientation was observed in the 27 Å Al2 O3 films. The full width at half maximum of the γ- Al2 O3 (222) rocking curve is 0.056°, indicating a lack of mosaic spread and a high-quality crystalline film. Twinning around the γ- Al2 O3  axis was the only defect observed in these films.
Place, publisher, year, edition, pages
2007. Vol. 90, no 6, 061916- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-26526DOI: 10.1063/1.2435978͔ISI: 000244162300033OAI: oai:DiVA.org:uu-26526DiVA: diva2:54300