Mist-chemical vapor deposition grown-single crystalline oxide semiconductors

Abstract

As a candidate for realizing next-generation electrical devices, tin dioxide (SnO₂) was grown on 2-inch diameter m-plane sapphire substrates by mist-chemical vapor deposition at atmospheric pressure. The prepared films were then characterized by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray diffraction (XRD) and electron backscatter diffraction (EBSD). In spite of the fact that XRD and EBSD measurements indicated that SnO₂ films were epitaxially grown on the substrates under optimized growth condition, the AFM and SEM images showed relatively rough surface morphology. For improving the surface morphology, the second SnO₂ layer was overgrown on the above single crystalline SnO₂ thin film, which functioned as a buffer layer. As a result, SEM and AFM measurements indicated drastically improved surface morphology using the buffer layer.