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Asymmetry in indentation-induced mechanical damage on Si (111) surfaces is investigated by using optical microscopy and X-ray diffraction topography. Cracks, residual strain fields and anneal-induced dislocation rosettes around the indentation are found to represent the asymmetries in the [2] and reverse [11] directions on the (111) surface. The crack formation along three <112> directions and the residual strain field distribution along <112> directions are discussed in terms of dislocation reaction and silicon crystal structure, respectively.

Scratch-induced mechanical damage on silicon (111) surfaces, in particular the fractures, residual strain fields and anneal-induced dislocations generated by <112> and <110> direction scratches, is investigated by optical microscopy, X-ray diffraction topography and the copper decoration method. The asymmetry in this damage in the [11] and reverse [2] directions is observed. The asymmetries are correlated with each other and are discussed in terms of the inclined (11) cleavage plane whose intersection with the (111) surface is perpendicular to the <112> direction.

Growth striations in a liquid encapusulated Czochralski (LEC) GaP crystal doped with Te at the concentration of 6×1017cm-3was examined by the 90°-angle light scattering method. The growth striations were manifested as a periodical fluctuation in the scattering intensity along the growth direction in the core region of the crystal. The striations were found to be clearly correlated with chemical etching pattern, periodical Te fluctuation detected by electron-probe X-ray microanalysis and periodical cathodoluminescence signal by Te donor. The origin of the striated scattering pattern is attributed to the periodical distribution of the scattering centers formed by the preferential precipitation of excess Te on grown-in dislocations.