Optimized local lifetime control for the superior IGBTs

Application of local lifetime control by helium ion irradiation was studied to improve an IGBT's performance. Light ion irradiation enables the formation of recombination layers in silicon power devices at favorable area by accommodation of ion accelerative voltage, resulting in reduction of turn-off power dissipation loss. In a practical application of the ion irradiation, relatively large scattering of performance could take place because of the relatively large scattering of Si wafer thickness. However, over 20% reduction of the turn-off loss was successfully achieved without a large scattering of trade-off characteristics by an irradiation method which utilizes the defects formed by the passing ions for the first time.