| 主权项 |
1. A semiconductor power device comprising:
a first electrode and a second electrode; a breakdown voltage holding layer, the breakdown voltage holding layer being made of a semiconductor having a predetermined thickness and a predetermined impurity concentration, the first electrode and the second electrode being joined to the breakdown voltage holding layer, the breakdown voltage holding layer having an active region in which carriers to generate electric conduction between the first electrode and the second electrode move; and an insulation film, the insulation film being formed on the breakdown voltage holding layer, the insulation film having a high dielectric-constant portion having a higher dielectric constant than SiO2 at a part contiguous to the breakdown voltage holding layer, wherein, in the active region, the breakdown voltage holding layer has a field-effect transistor structure including a first conductivity type source region, a second conductivity type body region contiguous to the source region, a first conductivity type drift region contiguous to the body region, and a gate trench penetrating the source region and the body region from a surface of the breakdown voltage holding layer, the first electrode includes a source electrode electrically connected to the source region, and the second electrode includes a drain electrode electrically connected to the drift region, wherein the insulation film has a laminated structure including a low dielectric-constant insulation film having a lower dielectric constant than that of the high dielectric-constant portion and being in contact with the body region, and a high dielectric-constant insulation film as the high dielectric-constant portion stacked on the low dielectric-constant insulation film and partly extending from the laminated structure to be contiguous to the drift region, wherein the insulation film has
a two-layer structure consisting of the low dielectric-constant insulation film and the high dielectric-constant insulation film in a part on a side surface of the gate trench, anda single-layer structure consisting of only the high dielectric-constant insulation film in a part on a bottom surface of the gate trench, and the source electrode is in contact with a part of an upper surface of the source region. |
