LBIC investigation of impurity-dislocation interaction in FZ silicon wafers

In the present work, dislocation arrays are investigated in float zone (FZ) grown silicon wafers by the light beam induced current (LBIC) mapping technique at different wavelengths and by deep level transient spectroscopy (DLTS). The LBIC technique appears to be able to recognize and to detect these arrays and to evaluate their recombination strength. In FZ dislocated wafers, a phosphorus diffusion attenuates strongly the LBIC contrast of dislocations, depending on the duration and temperature of the treatment. Electrical activity at room temperature of the defects, still physically present, seems to disappear. Simultaneously, the peak intensity of DLTS spectra related to dislocations is reduced and this evolution depends on the phosphorus diffusion temperature and duration.