Field-effect transistor, complementary field-effect transistor, and method of manufacturing field-effect transistor

A method of manufacturing a field-effect transistor comprising:

• depositing a mask on a principal surface of a substrate made of single-crystal silicon having a {100} plane as said principal surface;
• sequentially removing said mask and said substrate to form a concave while forming an element forming region beside said concave;
• shrinking said sidewall of said mask deposited in said depositing from said concave toward said element forming region to expose a part of said principal surface from said mask;
• after said exposing said part of said principal surface from said mask, oxidizing the whole surface of said substrate to form an inclined surface oblique to said principal surface in a <010> crystal axis direction or an axis direction substantially equivalent to said <010> crystal axis direction in said substrate exposed from said mask;
• filling said concave with an insulating film to form an element isolation region;
• and
• removing said mask to form a gate electrode extending substantially in said <010> crystal axis direction of said single-crystal silicon or in the axis direction substantially equivalent to said <010> crystal axis direction on said substrate in said element forming region comprising said inclined surface.