Observation of Damaged Layers in 4H-SiC Substrates by Mirror Projection Electron Microscope

Surface defects with scratch-like appearances are often observed locally on 4H-SiC wafers after epitaxial growth. We evaluated such damaged layer which is the cause of local step bunching using Mirror Projection Microscope (MPJ). As a result, MPJ can be detected l damaged layer which could not be detected using Synchrotron X-ray topography, even if these defects are extremely flat surface, no morphology, damaged layer is used to exist on the subsurface region. Thus, MPJ can be detected dislocation loops on the subsurface region of damage, it is effective to elucidate damaged layer of polishing process, MPJ is to be one of the candidates for inspection techniques of the damaged layer at substrate surface.