Mist-chemical vapor deposition grown-single crystalline oxide semiconductors
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.