Shorter turn-off times in insulated gate transistors by proton implantation

Proton implantation has been used to shorten the turnoff time of insulated gate transistors. A narrow region of low carrier lifetime was created at 100-µm depth by implanting 3.1-MeV protons. As with other techniques of lifetime control, an increase in forward voltage drop with decreasing turn-off time was observed. The use of localized lifetime control provides the opportunity of improving the trade-off relationship between turn-off time and forward voltage drop at the device's operating current. A definite improvement in trade-off curves was observed when the new technique of proton implantation was compared to the method of electron irradiation.