A light detection device capable of relaxing an electric field at an interface between an insulating film and a semiconductor substrate. The present technology includes a semiconductor substrate, a first trench and a second trench each having a lattice shape and provided on a first surface of the semiconductor substrate, an insulating film covering inner side surfaces of the first and second trenches and the first surface, an anode electrode embedded in the first trench, P type, P+ type, and N+ type semiconductor regions, a cathode contact in an element region, and a cathode electrode. The insulating film includes at least a first region and a second region. The second region includes a portion at a depth at which a distance between a third semiconductor region and a first electrode is minimized. A dielectric constant of the second region is lower than a dielectric constant of the first region.

The semiconductor device includes a semiconductor chip that has a first principal surface, a withstand-voltage holding structure in a peripheral region in the first principal surface, a plurality of first conductive layers that are formed in the first principal surface, a second conductive layer overlaps with a space between the plurality of mutually adjacent first conductive layers in a plan view, and a protective layer that covers the plurality of first conductive layers and the second conductive layer.

A semiconductor device includes a chip with a main surface, featuring a first conductivity type base region. A trench gate structure penetrates the base region, while a second conductivity type emitter region is formed along the trench gate structure on the surface. Between the bottom of the base region and the emitter region, a higher impurity concentration in-base region is present. An insulating film covers the main surface, featuring a connection hole that exposes part of the emitter region at a distance from the in-base region. A connection electrode is positioned in the connection hole, electrically connecting the base and emitter regions.