SILICON CARBIDE SEMICONDUCTOR DEVICE AND PROCESS FOR PRODUCING THE SAME

摘要

A silicon carbide semiconductor device having excellent performance characteristics and a method of manufacturing the same are obtained. An extended terrace surface is formed at a surface of an initial growth layer (11) on a 4H-SiC substrate (10) by annealing with the initial growth layer (11) covered with an Si film, and then a new growth layer (21) is epitaxially grown on the initial growth layer (11). A 3C-SiC portion (21a) having a polytype stable at a low temperature is grown on the extended terrace surface, and a 4H-SiC portion (21b) is grown on the other region. A trench (Tr) is formed by selectively removing the 3C-SiC portion (21a) with the 4H-SiC portion (21b) remaining, and a gate electrode (27) of a UMOSFET is formed in the trench (Tr). A channel region of the UMOSFET can be controlled to have a low-order surface, and a silicon carbide semiconductor device having high channel mobility and excellent performance characteristics is obtained.