Experimental determination of lifetime engineering effects on free-carrier concentration

The effects of lifetime engineering processes in fast recovery power diodes are measured by using an internal IR-laser deflection (IIR-LD) set-up. To evidence the local lifetime killing effects on such devices, a comparison between the measured physical parameters of irradiated and unirradiated diodes, free-carrier concentration and their decay time, is performed. A reduction of free-carrier concentration profile and local lifetime is observed in the region of the ion penetration range. Furthermore, even at low fluences, ion irradiation impact on the free-carrier concentration has been measured. The measured free-carrier concentrations are corroborated by simulation results, obtaining good qualitative agreement