SEMICONDUCTOR DEVICE

摘要

A MOSFET (1) includes a silicon carbide substrate (10), an active layer (20), a gate oxide film (30), and a gate electrode (40). The active layer (20) includes a p type body region (22) in which an inversion layer is formed when the gate electrode (40) is fed with a voltage. The inversion layer has an electron mobility µ dependent more strongly on an acceptor concentration N a of a channel region (29) of the p type body region (22), as compared with a dependency of the electron mobility µ being proportional to the reciprocal of the acceptor concentration N a . The acceptor concentration N a in the channel region (29) of the p type body region (22) is not less than 1 × 10 16 cm -3 and not more than 2 × 10 18 cm -3 . The channel length (L) is equal to or smaller than 0.43 µm. The channel length (L) is equal to or longer than a spreading width d of a depletion layer in the channel region (29). The spreading width d is expressed by d = D·N a -C .