Semiconductor device and method for driving same

A semiconductor device includes: a first electrode; a first semiconductor layer located on the first electrode in a diode region; a second semiconductor layer located on the first electrode in an IGBT region; a third semiconductor layer located in the diode region, the boundary region, and the IGBT region and positioned on the first semiconductor layer and the second semiconductor layer; a fourth semiconductor layer located on the third semiconductor layer in the boundary region and the IGBT region; a fifth semiconductor layer located on the third semiconductor layer and the fourth semiconductor layer; a second electrode located in the diode region; a third electrode located in the IGBT region; and a fourth electrode extending from an upper surface of the fifth semiconductor layer toward the third semiconductor layer in the boundary region and electrically insulated from the third electrode.