X-RAY-ANALYSIS OF INTERNAL-STRESSES IN CRYSTALS .2. LATTICE-DISTORTIONS DUE TO RESIDUAL STRAINS IN CRYSTALS GROWN FROM MELTS

Lattice distortions are analyzed in dislocation-containing semiconductor crystals with inhomogeneously distributed point defects (impurities, dopants, intrinsic point defects). Crystal-lattice distortions are determined which appear as result of plastic deformation due to axial and radial temperature differences in a growing crystal. Such processes lead to bending of a crystal slab and distortions in the slab plane, and can be separated with the aid of X-ray measurements of the components of the crystal-lattice distortion tensor. It is shown that the contributions to the lattice distortions from dislocations and inhomogeneously distributed point defects can also be separated, and therefore both sources of internal stresses can simultaneously be determined from X-ray data on lattice distortions. The results of the X-ray investigations of dislocation-containing undoped and doped single crystals are analyzed. The ways to make experiments more informative are discussed.