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) ma pping technique at different wavelengths and by deep level transient s pectroscopy (DLTS). The LBIC technique appears to be able to recognize and to detect these arrays and to evaluate their recombination streng th. In FZ dislocated wafers, a phosphorus diffusion attenuates strongl y the LBIC contrast of dislocations, depending on the duration and tem perature of the treatment. Electrical activity at room temperature of the defects, still physically present, seems to disappear. Simultaneou sly, the peak intensity of DLTS spectra related to dislocations is red uced and this evolution depends on the phosphorus diffusion temperatur e and duration.