Trench MOS schottky diode and method for producing same

A method for producing a trench MOS Schottky diode;

• comprising:
• preparing a stacked body that comprises a first semiconductor layer comprising a Ga2O3-based single crystal and a second semiconductor layer comprising a Ga2O3-based single crystal;
• forming a trench on the second semiconductor layer by dry etching so as to be opened on a surface opposite to the first semiconductor layer;
• performing annealing treatment to reduce the thickness of an insulating dry-etching-damaged layer that is formed in the second semiconductor layer in a region including the inner surface of the trench;
• forming an insulating film so as to cover the inner surface of the trench of the second semiconductor layer;
• burying a trench electrode in the trench of the second semiconductor layer so as to be covered with the insulating film;
• forming an anode electrode on the surface of the second semiconductor layer opposite to the first semiconductor layer so as to be in contact with the trench electrode;
• and
• forming a cathode electrode on a surface of the first semiconductor layer opposite to the second semiconductor layer,
• wherein the annealing treatment is performed after forming the trench on the second semiconductor layer by the dry etching and before forming the insulating film on the inner surface of the trench of the second semiconductor layer.

A method for producing a trench MOS Schottky diode;

• comprising:
• preparing a stacked body that comprises a first semiconductor layer comprising a Ga2O3-based single crystal and a second semiconductor layer comprising a Ga2O3-based single crystal;
• forming a trench on the second semiconductor layer by dry etching so as to be opened on a surface opposite to the first semiconductor layer;
• performing wet etching to remove an insulating dry-etching-damaged layer that is formed in the second semiconductor layer in a region including the inner surface of the trench;
• forming an insulating film so as to cover the inner surface of the trench of the second semiconductor layer;
• burying a trench electrode in the trench of the second semiconductor layer so as to be covered with the insulating film;
• forming an anode electrode on the surface of the second semiconductor layer opposite to the first semiconductor layer so as to be in contact with the trench electrode;
• and
• forming a cathode electrode on a surface of the first semiconductor layer opposite to the second semiconductor layer,
• wherein the wet etching is performed after an annealing treatment to the region including the inner surface of the trench, and
• wherein both of the annealing treatment and the wet etching are performed after forming the trench on the second semiconductor layer by the dry etching and before forming the insulating film on the inner surface of the trench of the second semiconductor layer.