Abstract: A semiconductor device according to an aspect of the present disclosure, includes a semiconductor layer in which a trench is formed, a buried electrode provided inside the trench, an upper electrode provided above the buried electrode inside the trench, an insulating film provided inside the trench, a first electrode provided on an upper surface of the semiconductor layer, and a second electrode provided on a lower surface of the semiconductor layer, wherein the insulating film includes a first portion between the buried electrode and a side wall of the trench, a second portion between the upper electrode and the side wall of the trench, and a third portion between the buried electrode and the upper electrode, and a lower surface of the upper electrode has a dent in a central portion.

Abstract: A predetermined relational expression holds where a first distance along the in-plane direction from a channel of the first semiconductor layer to a third semiconductor layer that is the other of the collector layer and the cathode layer is designated as W, a second distance from the channel of the first semiconductor layer to the second semiconductor layer is designated as S, and a diffusion coefficient and a lifetime of a part of the semiconductor substrate between the channel of the first semiconductor layer and the third semiconductor layer are designated as D and ?, respectively.

Abstract: A semiconductor device includes an IGBT region and a diode region provided to be adjacent to each other in a semiconductor substrate further includes: a boundary trench having, in a position in which the IGBT region and the diode region are adjacent to each other in plan view, a bottom surface positioned in a drift layer to be deeper than an active trench or a dummy trench, and one side wall and another side wall that face each other; and a boundary trench gate electrode, which faces a base layer, an anode layer, and the drift layer via a boundary trench insulating film and is provided from the one side wall to the other side wall of the boundary trench across a region that faces the drift layer in the boundary trench.

Abstract: A predetermined relational expression holds where a first distance along the in-plane direction from a channel of the first semiconductor layer to a third semiconductor layer that is the other of the collector layer and the cathode layer is designated as W, a second distance from the channel of the first semiconductor layer to the second semiconductor layer is designated as S, and a diffusion coefficient and a lifetime of a part of the semiconductor substrate between the channel of the first semiconductor layer and the third semiconductor layer are designated as D and ?, respectively.

Abstract: A semiconductor device includes an IGBT region and a diode region provided to be adjacent to each other in a semiconductor substrate further includes: a boundary trench having, in a position in which the IGBT region and the diode region are adjacent to each other in plan view, a bottom surface positioned in a drift layer to be deeper than an active trench or a dummy trench, and one side wall and another side wall that face each other; and a boundary trench gate electrode, which faces a base layer, an anode layer, and the drift layer via a boundary trench insulating film and is provided from the one side wall to the other side wall of the boundary trench across a region that faces the drift layer in the boundary trench.