Power semiconductor device and method for manufacturing the same

摘要

A power semiconductor device includes a first semiconductor layer of a first conductivity type, a first drift layer, and a second drift layer. The first drift layer includes a first epitaxial layer of the first conductivity type, a plurality of first first-conductivity-type pillar layers, and a plurality of first second-conductivity-type pillar layers. The second drift layer is formed on the first drift layer and includes a second epitaxial layer of the first conductivity type, a plurality of second second-conductivity-type pillar layers, a plurality of second first-conductivity-type pillar layers, a plurality of third second-conductivity-type pillar layers, and a plurality of third first-conductivity-type pillar layers. The plurality of second second-conductivity-type pillar layers are connected to the first second-conductivity-type pillar layers. The plurality of second first-conductivity-type pillar layers are connected to the first first-conductivity-type pillar layers. The plurality of third second-conductivity-type pillar layers are arranged on the first epitaxial layer.

主权项

1. A semiconductor device comprising:
a semiconductor layer of a first-conductivity-type; a first electrode connected to the semiconductor layer; a base layer of a second-conductivity-type selectively provided in a device section at a surface of the semiconductor layer; a source layer of the first-conductivity-type selectively provided at a surface of the base layer; a first pillar layer of the second-conductivity-type connected to the base layer, the first pillar layer being provided in portions spaced along a first direction parallel to the first electrode; a gate electrode provided via a gate insulating film on the source layer, the base layer, and the semiconductor layer; a second electrode connected to the source layer and the base layer; a second pillar layer of the second-conductivity-type provided in a termination section and extending from the surface of the semiconductor layer into the semiconductor layer along a second direction perpendicular to the first direction, the termination section surrounding the device section in a plane parallel to the first electrode; and a semiconductor region of the first-conductivity-type provided between the first electrode and the second pillar layer, wherein a concentration of first-conductivity-type impurities in the semiconductor region is lower than a concentration of first-conductivity-type impurities in the semiconductor layer, wherein a shortest distance along the second direction from the first pillar layer to the first electrode is less than a shortest distance along the second direction from the second pillar layer to the first electrode.