Patent ID: 8445983

Claim:
A semiconductor device for performing photoelectric conversion of incident light, comprising: a substrate formed of one of an n-type semiconductor and a p-type semiconductor; a well region having a predetermined depth and formed of the other of the n-type semiconductor and the p-type semiconductor in a predetermined region of the substrate; a depletion layer generated in a vicinity of a junction interface between the substrate and the well region; a first trench provided so as to remove the junction interface on sides of the well region, the first trench having a depth equal to a height up to a top portion of the depletion layer generated on a bottom side of the well region and having a width extending to a heavily doped region formed in and at a center of the well region in a width direction thereof so that the well region is reduced to only a region under the heavily doped region; a second trench formed at an end of a bottom of the first trench and provided so as to remove the junction interface on the sides of the well region, the second trench having a depth larger than that of a portion of the depletion layer generated on the bottom side of the well region and having a width larger than that of portions of the depletion layer generated on the sides of the well region; and an insulator buried into each the first trench and the second trench.