| abstract |
A method of manufacturing a semiconductor device having an insulated gate bipolar transistor portion and a freewheeling diode portion. The method includes introducing an impurity to a rear surface of a semiconductor substrate, performing first heat treating to activate the impurity to form a field stop layer, performing a first irradiation to irradiate light ions from the rear surface of semiconductor substrate to form, in the semiconductor substrate, a first low-lifetime region, performing a second irradiation to irradiate the light ions from the rear surface of the semiconductor substrate to form, in the field stop layer, a second low-lifetime region, and performing second heat treating to reduce a density of defects generated in the field stop layer when the second irradiation is performed. Each of the first and second low-lifetime regions has a carrier lifetime thereof shorter than that of any region of the semiconductor device other than the first and second low-lifetime regions. |