Semiconductor device and method for manufacturing the same

摘要

According to one embodiment, a semiconductor device includes a first, a second, a third, a fourth semiconductor region, a control electrode, and an insulating film. The first region contains silicon carbide. The second region is provided on the first region and contains silicon carbide. The third region is provided on the second region and contains silicon carbide. The fourth region is provided on the third region and contains silicon carbide. The control electrode is provided in a trench. The trench is formed in the fourth, the third, and the second semiconductor region. The insulating film is provided between a side surface of the trench and the control electrode. The insulating film contains a high-dielectric constant region. The high-dielectric constant region contacts with at least the third semiconductor region. The high-dielectric constant region has a higher dielectric constant than a dielectric constant of silicon oxide.

主权项

1. A semiconductor device manufacturing method comprising:
forming a second semiconductor region containing silicon carbide of a first conductivity type on a first semiconductor region, the first semiconductor region containing silicon carbide; forming a third semiconductor region containing silicon carbide of a second conductivity type on the second semiconductor region; forming a fourth semiconductor region containing silicon carbide of the first conductivity type on the third semiconductor region; forming a trench in the fourth semiconductor region, the third semiconductor region, and the second semiconductor region; forming an insulating film on a side surface and a bottom surface of the trench; forming a first control electrode portion contacting with the insulating film, the first control electrode portion including a contacting region being in contact with at least the third semiconductor region; adding a material in the contacting region in the trench, the material being such that a dielectric constant of a compound of an oxide or nitride of the material is higher than a dielectric constant of silicon oxide; and forming a high-dielectric constant region in a region of the insulating film that is in contact with at least the third semiconductor region by diffusing the material.