Interfacial structure of oxidized AlN(0002)/Si(111) thin film - art. no. 044908

摘要

We present an interfacial structure formed during the thermal oxidation of epitaxial AlN(0002)/Si(111) thin film investigated by synchrotron x-ray scattering and transmission electron microscopy. We found that a crystalline interlayer with a thickness of similar to 30 A is formed as the AlN film transforms to epitaxial cubic spinel gamma-Al2O3 during the initial stage of oxidation. The lattice spacing of such crystalline interlayer is about 5.441 A, and we believe it to be an aluminum-silicate (AlxSiO2-delta) phase having a diamond structure. As the annealing proceeds further, an amorphous-SiO2 (alpha-SiO2) layer is formed between the crystalline AlxSiO2-delta interlayer and the resultant gamma-Al2O3 film. The alpha-SiO2 layer grows as the annealing time increases, which indicates that Si atoms diffuse continuously through the crystalline AlxSiO2-delta interlayer. (c) 2005 American Institute of Physics.