Revealing the structural disturbances in Czochralski silicon by high temperature-pressure treatment

High-resolution X-ray diffraction and topographic methods were used to characterize the structural defects in single crystalline Czochralski-grown silicon (Cz-Si) with various oxygen concentrations. Annealing under hydrostatic pressure (HP) was applied for revealing the defects existing in Cz-Si wafers. The high pressure-high temperature treatment of as-grown Cz-Si at 1127 °C under 1.1 GPa resulted in enhanced oxygen precipitation, mostly at the initially existing structural disturbances, while annealing under 107 Pa did not affect the defect structure in the sample. The visibility of defects after the treatment under high pressure can be related to HP-induced strain at the boundary between the defect and the Si matrix, to increased defect dimensions due to HP-stimulated oxygen precipitation and to decreased concentration of defects. Precipitation of oxygen on small structural inhomogeneities and agglomeration of small defects assist in revealing the structural disturbances pre-existing in Cz-Si.