Abstract

Both single and CVD diamonds were mechanically polished by using grinding wheels of #400 or #1500. The polished surfaces were smooth and no cracks could not be observed by a microscope. These surfaces were exposed in hydrogen plasma for 1 hour, cracks appeared on the surface. For the single crystal diamond, the crack shape exhibited the relation with crystallographic orientation of the polished surface and polishing direction. Also on the CVD diamond cracks came out by etching but the size is smaller than those on a single crystal diamond.