Study of Surface Morphologies of On-Axis 6H-SiC Wafer after High-Temperature Etching and Epitaxial Growth

Abstract

Gas etching and homoepitaxial growth on a nominally on-axis 2-inch 6H-SiC (0001) Si-face were studied. Regular steps with one unit cell height and complex pattern with facets and steps were observed after gas etching in the central region and edge region, respectively. The homoepitaxial growth shows that the complex (facets & steps) pattern expands and merges during the growth to bring on a rough epi-layer surface in the edge region. The steps with one unit cell height on the substrate split into steps with bilayers on the epilayer. The different lateral growth rates of <11-20>- and <1-100>-orientated steps make the width of steps orientated to <11-20> much larger than the ones orientated to <1-100>.