Surface examining apparatus and method

摘要: The surface of a polished semiconductor wafer is examined by an apparatus comprising light source, first optical means for converging the to parallel and projecting it onto be second reflected receiving screen. If has defect, such as crystal imperfection, forms very slight recess or wave, example, having sub-micron depth opening diameter several mm. When above-mentioned apparatus, specific shading patterns, lines, stripes dots are projected on light-receiving screen, thereby making detection defects easy even subject automation.