A new Internal Transparent Collector IGB

A new Internal Transparent Collector Insulated Gate Bipolar Transistor (ITC-IGBT) is proposed, and 600V ITC-IGBTs with planar gates are fabricated. The structure of the new IGBT is similar to that of PT-IGBT, but a very low carrier lifetime control layer (LCLCL) is introduced in the collector region near the p-collector/ n-buffer junction. The LCLCL is a nano vacancy layer which is induced by high dose helium irradiation and followed by annealing. The devices´ I-V characteristics under room and high temperatures and turn-off time under room temperature are measured. The ITC-IGBTs´ current density at zero temperature coefficient (ZTC) point is about 80A/cm², which is much lower than the rated value (the current density correlated to rated current is normally 150-200A/cm²). For comparison, PT-IGBTs with the same structural dimensions and using electron irradiation are also fabricated. The ITC-IGBTs´ trade-off between V_CEsat and turn-off time is better than that of the normal PT-IGBT. For example, the t_f of the ITC-IGBT at V_CEsat=1.6V is about 360ns, only 60% that of the PT-IGBT.