Effect of Gamma-Ray Irradiation on the Performance of 600V NPT-IGBT

Fast neutron irradiation using nuclear reactors is an effective method to improve switching loss and short circuit durability of power semiconductor (IGBT and IGT etc.). However, not only fast neutrons but also thermal neutrons and gamma-rays exist in the nuclear reactor. Thermal neutrons give rise to the doping effect by transmuted atoms. Gamma-gays heat the target and recoil atoms remaining damages, which results in an undesirable energy level within the energy band gap. Research on various kinds of radiation damages is necessary to improve the IGBT device through fast neutron irradiation. The radiation damages are known to be caused by Total Ionizing Dose (TID) effect and Single Event Effect (SEE) and Displacement Damage. Especially, the TID effect deteriorates the electrical properties such as leakage current and the threshold voltage of a power semiconductor. In this study, the TID effect by gamma-ray irradiation on electrical properties was evaluated for 600 V NPT-IGBT. This work can confirm the effect of the gamma-ray irradiation on the electrical properties of 600 V NPTIGBT. Gamma-ray generates lattice defects in the gate oxide and Si-SiO₂ interface of the IGBT.