4h-SiC semiconductor element and semiconductor device

摘要

A trench groove is formed and a silicon oxide film is buried in the periphery of a channel region of (0001) surface 4h-SiC semiconductor element. The oxide film in the trench groove is defined in such a planar layout that a tensile strain is applied along the direction of the c-axis and a compressive strain is applied along two or more of axes on a plane perpendicular to the c-axis. For example, trench grooves buried with an oxide film may be configured to such a layout that they are in a trigonal shape surrounding the channel, or are arranged symmetrically with respect to the channel as a center when arranged discretely.

主权项

1. A 4h-SiC semiconductor element comprising:
a 4h-SiC substrate; a drift region having a c-axis in a direction perpendicular to the surface of the substrate and formed on the side of the surface of the substrate by using 4h-S C; a base region formed on the side of the surface of the drift region using 4h-SiC; a source region formed on the side of the surface of the base region by using 4h-SiC; a source electrode formed on the side of a surface of the source region by using 4h-SiC; a trench-shaped gate electrode covering the channel region of the base region; a gate insulating film formed at the boundary between the gate electrode and the channel region; a drain region formed on the side of a back of the 4h-SiC substrate by using 4h-SiC; a drain electrode formed on the side of the back of the drain region; and a trench-shaped buried oxide film layer of applying a compressive strain in a direction of two axes or more on a plane perpendicular to the c-axis of the channel region and applying a tensile strain along the direction of the c-axis.