Semiconductor element

摘要

In a semiconductor element, a body region of a second conductivity type includes a first body region in contact with a surface of a first silicon carbide semiconductor layer, and a second body region in contact with a bottom surface of the body region of the second conductivity type. The impurity concentration of the first body region is twice or more the impurity concentration of the second body region. A second silicon carbide semiconductor layer of a first conductivity type, which is a channel layer, has an impurity concentration distribution in a direction perpendicular to a semiconductor substrate, and an impurity concentration on a side in contact with the gate insulating film is lower than an impurity concentration on a side in contact with the first body region.

主权项

1. A semiconductor element, comprising:
a semiconductor substrate of a first conductivity type; a first silicon carbide semiconductor layer of the first conductivity type located on a principal surface of the semiconductor substrate; a body region of a second conductivity type located in the first silicon carbide semiconductor layer; an impurity region of the first conductivity type located in the body region; a second silicon carbide semiconductor layer of the first conductivity type which is located on the first silicon carbide semiconductor layer and is in contact with at least part of the body region and at least part of the impurity region; a gate insulating film on the second silicon carbide semiconductor layer; a gate electrode on the gate insulating film; a first ohmic electrode electrically connected to the impurity region; and a second ohmic electrode provided on a back surface of the semiconductor substrate, wherein the body region of the second conductivity type includes, in a portion under the gate electrode, a first body region in contact with a surface of the first silicon carbide semiconductor layer, and a second body region in contact with a bottom surface of the body region of the second conductivity type, and an impurity concentration of the first body region is twice or more an impurity concentration of the second body region, and the second silicon carbide semiconductor layer of the first conductivity type has an impurity concentration distribution in a direction perpendicular to the semiconductor substrate, and an impurity concentration on a side in contact with the gate insulating film is lower than an impurity concentration on a side in contact with the first body region.