SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE FABRICATION METHOD

摘要

An n− drift layer is a parallel pn layer having an n-type region and a p-type region are alternately arranged in the direction parallel to the main surface so as to come into contact with each other, and have a width in a direction parallel to the main surface of the substrate which is less than a length in a direction perpendicular to the main surface of the substrate. A second-main-surface-side lower end portion of the p-type region has a structure in which a high-concentration lower end portion and a low-concentration lower end portion of a p-type low-concentration region are repeated at a predetermined pitch in the direction parallel to the main surface of the substrate. It is possible to provide a super junction MOS semiconductor device which can improve a trade-off relationship between turn-off loss and turn-off dv/dt and improve avalanche resistance.

主权项

1. A semiconductor device comprising:
a metal-oxide film-semiconductor insulated gate structure that is provided on a first main surface of a first-conductivity-type semiconductor substrate; and a drift layer that is provided between the first main surface of the first-conductivity-type semiconductor substrate and a second main surface opposite to the first main surface, wherein the drift layer is a parallel pn layer including a first-conductivity-type region in which a width in a direction parallel to the first main surface is less than a length in a direction perpendicular to the first main surface and a second-conductivity-type region in which a width in the direction parallel to the first main surface is less than a length in the direction perpendicular to the first main surface, the first-conductivity-type region and the second-conductivity-type region are alternately arranged in the direction parallel to the first main surface so as to come into contact with each other, a pn junction between the first-conductivity-type region and the second-conductivity-type region extends in the direction perpendicular to the first main surface, and a second-conductivity-type second-main-surface-side region having an impurity concentration distribution in which high impurity concentration and low impurity concentration are repeated at a predetermined pitch in the direction parallel to the first main surface and in a second direction perpendicular to a first direction in which the first-conductivity-type region and the second-conductivity-type region are arranged in a line is provided at an end of the second-conductivity-type region which is close to the second main surface.