Semiconductor device, schottky barrier diode, electronic apparatus, and method of producing semiconductor device

A method of producing a semiconductor device comprising semiconductor layers, an anode electrode, and a cathode electrode, wherein the semiconductor layers include a composition change layer, the anode electrode is electrically connected to one of principal surfaces of the composition change layer through a formation of a Schottky junction between the anode electrode and a part of the semiconductor layers, the cathode electrode is electrically connected to the other of the principal surfaces of the composition change layer through a formation of a junction between the cathode electrode and another part of the semiconductor layers, the anode electrode and the cathode electrode are capable of applying a voltage to the composition change layer in a direction perpendicular to the principal surface,

• the composition change layer has composition that changes from a cathode electrode side toward an anode electrode side in the direction perpendicular to the principal surface of the composition change layer, has a negative polarization charge that is generated due to the composition that changes, and contains a donor impurity;
• the method comprising:
• a semiconductor layer formation step of forming the semiconductor layers;
• and an electrode junction step of forming a Schottky junction between the anode electrode and a part of the semiconductor layers and of forming a junction between the cathode electrode and another part of the semiconductor layers, wherein the semiconductor layer formation step comprises a composition change layer formation step,
• in the composition change layer formation step, the composition change layer is formed such that it generates a negative polarization charge due to its composition that changes in the direction perpendicular to the principal surface and it contains a donor impurity, and
• in the electrode junction step, the anode electrode and the cathode electrode are formed so as to be capable of applying a voltage to the composition change layer in the direction perpendicular to the principal surface;
• and
• wherein in the composition change layer formation step, the composition change layer is formed such that the Al composition ratio x of the composition change layer decreases continuously from x0 to xA from the cathode electrode side toward the anode electrode side in the direction perpendicular to the principal surface of the composition change layer;
• and
• wherein in the composition change layer formation step, the composition change layer is formed such that the Al composition ratio x of the composition change layer decreases continuously from x0 to xA from the cathode electrode side toward the anode electrode side in the direction perpendicular to the principal surface of the composition change layer, and the decreasing gradient of the Al composition ratio of the composition change layer is a steep gradient from the cathode electrode side toward the anode electrode side.