Semiconductor device

A semiconductor device, comprising:

• a semiconductor part;
• a first electrode on a back surface of the semiconductor part;
• a second electrode on a front surface of the semiconductor part;
• a third electrode provided between the semiconductor part and the second electrode, the semiconductor part having a trench at the front surface side, the third electrode being provided inside the trench of the semiconductor part;
• a fourth electrode provided inside the trench of the semiconductor part, the fourth electrode being provided between the first electrode and the third electrode;
• a first insulating portion electrically insulating the third electrode from the semiconductor part;
• a second insulating portion electrically insulating the third electrode from the second electrode;
• a third insulating portion electrically insulating the fourth electrode from the semiconductor part;
• a fourth insulating portion electrically insulating the fourth electrode from the third electrode;
• and
• a fifth insulating portion including a first portion and a second portion, the first portion being provided inside the fourth electrode, the second portion extending outward of the fourth electrode, the second portion extending from the first portion in a first direction from the first electrode toward the second electrode,
• the semiconductor part including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and a third semiconductor layer of the first conductivity type,
• the first semiconductor layer extending between the first and second electrodes,
• the second semiconductor layer being provided between the first semiconductor layer and the second electrode, the second semiconductor layer facing the third electrode via the first insulating portion,
• the third semiconductor layer being selectively provided between the second semiconductor layer and the second electrode, the third semiconductor layer contacting the first insulating portion and being electrically connected to the second electrode.