An IGBT is provided comprising at least two first cells (1, 1′), each of which having an n doped source layer (2), a p doped base layer (3), an n doped enhancement layer (4), wherein the base layer (3) separates the source layer (2) from the enhancement layer (4), an n− doped drift layer (5) and a p doped collector layer (6). Two trench gate electrodes (7, 7′) are arranged on the lateral sides of the first cell (1, 1′).
The transistor comprises at least one second cell (15) between the trench gate electrodes (7, 7′) of two neighboured first cells (1, 1′), which has on the emitter side (90) a p+ doped well (8) and a further n doped enhancement layer (40, 40′) which separates the well (8) from the neighboured trench gate electrodes (7, 7′). An insulator layer stack (75) is arranged on top of the second cell (15) on the emitter side (90) to insulate the second cell (15) and the neighboured trench gate electrodes (7, 7′) from the metal emitter electrode (9), which consists of a first insulating layer (73) and a second insulating layer (74), wherein the insulator stack (75) has a thickness on top of the well (8) of a first layer thickness plus the second insulating layer thickness and a thickness on top of the gate layer (70, 70′) of the second insulating layer thickness, wherein each thickness of the first insulating layer (73) and the second insulating layer (74) is at least 700 nm.