Detection of junction failures and other defects in silicon and III-V devices using the LBIC technique in lateral configuration

A scanning light microscope was used to obtain light beam induced current (LBIC) profiles in samples containing a p-n junction either parallel or perpendicular to the surface scanned by the beam. Using this technique we studied the quality of the junction of InP(n)-InP(p) diodes, which are one of the intermediate structures obtained during the processing of InGaAsP/InP lasers. The same technique was successfully employed also for the quality control of silicon power diodes. It was thus demonstrated that the LBIC technique, operated in the standard and in the lateral configuration at a resolution better than 10 mu m, is a powerful, nondestructive tool which can be efficiently used for the quantitative measure of the damage present at any kind of diode junctions.