TRANSMISSION ELECTRON-MICROSCOPY CROSS-SECTIONAL OBSERVATION ON MECHANICALLY AND CHEMICALLY LAPPED SI (111) SURFACES

The (111) surfaces of Si single crystals, mechanically lapped by fine abrasives with different particle size or chemically etched, are observed from the cross-sectional direction by transmission electron microscopy (TEM). On the mechanically lapped surface the defect layers of several mu-m in thickness, containing blocks, grains and cracks along nearly {100}, {110} {111} and {112}, are formed. The size of grains as well as the misorientation between grains increases with increase of the particle size of abrasives. On the chemically etched surface, on the other hand, the defect density is so low that the crystal near the surface seems almost perfect. The prominent enhancement of X-ray integrated intensity from mechanically lapped surfaces can be related to the misorientation between grains.