Silicon carbide semiconductor device having high channel mobility and method for manufacturing the same

Abstract

A silicon carbide semiconductor device having a MOS structure includes: a substrate; a channel area in the substrate; a first impurity area; a second impurity area; a gate insulating film on the channel area; and a gate on the gate insulating film. The channel area provides an electric current path. The channel area and the gate insulating film have an interface therebetween. The interface includes a dangling bond, which is terminated by a hydrogen atom or a hydroxyl. The interface has a hydrogen concentration equal to or larger than 2.6×10 20 cm −3 .

1 . A silicon carbide semiconductor device having a MOS structure comprising:
 a substrate made of silicon carbide;   a channel area for providing an electric current path, wherein the channel area is made of silicon carbide and disposed in the substrate;   a first impurity area disposed on an upstream side of the electric current path;   a second impurity area disposed on a downstream side of the electric current path;   a gate insulating film disposed on a surface of the channel area; and   a gate disposed on the gate insulating film, wherein   the channel area provides the electric current path as a channel by controlling a voltage applied to the gate so that an electric current in the electric current path flowing between the first impurity area and the second impurity area is controlled,   the channel area and the gate insulating film have an interface therebetween,   the interface includes a dangling bond, which is terminated by a hydrogen atom or a hydroxyl, and   the interface has a hydrogen concentration equal to or larger than 2.6×10 20  cm −3 .   
   
   
       2 . The silicon carbide semiconductor device according to  claim 1 , wherein
 the interface includes another dangling bond, which is terminated by a nitrogen atom.   
   
   
       3 . The silicon carbide semiconductor device according to  claim 1 , wherein
 the substrate has a main surface, which is provided by a (11-20)-plane.   
   
   
       4 . The silicon carbide semiconductor device according to  claim 1 , wherein
 the hydrogen atom terminating the dangling bond has a desorbing amount, which represents a maximum peak in a range between 800° C. and 900° C.   
   
   
       5 - 49 . (canceled)