A method for producing a semiconductor device which includes: a
semiconductor base, a hetero semiconductor region made of a semiconductor
material different in band gap from a semiconductor material for the
semiconductor base, and so configured as to form a hetero junction in
combination with the semiconductor base, a gate insulating film so
configured as to contact with the hetero junction between the
semiconductor base and the hetero semiconductor region, a gate electrode
so configured as to contact with the gate insulating film, a source
electrode connected to the hetero semiconductor region, and a drain
electrode connected to the semiconductor base. The method includes:
forming the following in a self-aligning manner, by using a certain mask
material: a source contact hole for the source electrode, and the gate
electrode.