SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME

摘要

This silicon carbide semiconductor device comprises: a semiconductor layer (2) of a first conductivity type, which is formed on a semiconductor substrate (1) of the first conductivity type and has a low impurity concentration; a semiconductor layer (3) of a second conductivity type, which is selectively formed in the semiconductor layer (2) of the first conductivity type and has a high impurity concentration; a base layer (4) of the second conductivity type, which is formed on the surface of the semiconductor layer (3) of the second conductivity type and has a low impurity concentration; a source region (7) of the first conductivity type, which is selectively formed in the surface layer of the base layer (4); a well region (6) of the first conductivity type, which penetrates the base layer (4) from the surface to the semiconductor layer (2) of the first conductivity type; and a gate electrode (9) which is formed on the surface of the base layer (4) between the source region (7) and the well region (6), with a gate insulating film being interposed between the gate electrode (9) and the surface of the base layer (4). By connecting parts of respective semiconductor layers (3) of the second conductivity type of different cells with each other at the regions below the well regions (6) by means of connection parts (3a), a gate oxide film is not broken even when a high voltage is applied thereto and thus the silicon carbide semiconductor device has reliability and can be decreased in the on-resistance.