MOSFET having Schottky gate and bipolar device

A semiconductor device comprising:

• a semiconductor substrate having a surface layer in ohmic contact with a conductor and a deeper layer in Schottky contact with a conductor, the surface of the semiconductor substrate being formed with a recess penetrating the surface layer in ohmic contact with the conductor and reaching the deeper layer in Schottky contact with the conductor;
• a first conductor film extending in the recess of the semiconductor substrate from a bottom of the recess in a direction substantially at right angles to the bottom;
• a first insulating film formed on the surface of the semiconductor substrate such as to extend from the inside to the outside of the recess and in contact with one surface of the first conductor film;
• a second insulating film formed in the recess of the semiconductor substrate on the bottom of the recess and in contact with the other surface of the first conductor film;
• a second conductor film formed on surfaces of the first and the second insulating films and in contact with a top edge of the first conductor film;
• a third conductor film formed on the surface of the semiconductor substrate other than the recess and at a position to sandwich the first insulating film with the first conductor film;
• and
• a fourth conductor film formed on the surface of the semiconductor substrate and at a position to sandwich the second insulating film with the first conductor film.