Semiconductor device and method of manufacturing the semiconductor device

A method of manufacturing a semiconductor device including a semiconductor substrate of a first conductivity-type;

• a drift layer of the first conductivity-type formed on a first principal surface side of the semiconductor substrate;
• an anode layer of a second conductivity-type formed selectively along the drift layer and having a resistance that is lower than that of the drift layer;
• a cathode layer of the first conductivity-type formed on a surface layer of a second principal surface of the semiconductor substrate and contacting the drift layer;
• and a vacancy-oxygen complex defect region formed of complex defects of vacancies and oxygen, where the vacancy-oxygen complex defect region has a depth R in a direction from a boundary surface between the cathode layer and the drift layer toward a first principal surface of the semiconductor substrate, and the vacancy-oxygen complex defect region is provided at the depth R represented by 0<R≦t−W where resistivity of the semiconductor substrate is ρ, thickness from a pn junction between the anode layer and the drift layer to the cathode layer is t, and width of a depletion layer extending in the drift layer from the pn junction with a reverse bias voltage V applied to the pn junction is W and represented by 0.54×√(ρ×V), the method comprising:
• forming the vacancy-oxygen complex defect region by:
• locally forming a high-concentration oxygen region comprising oxygen having a high-concentration, at a predetermined position, by ion implantation of oxygen;
• and
• subsequently shortening carrier lifetime by electron beam irradiation.

A method of manufacturing a semiconductor device including a semiconductor substrate of a first conductivity-type;

• a drift layer of the first conductivity-type formed on a first principal surface of the semiconductor substrate;
• an anode layer of a second conductivity-type formed selectively along the drift layer and having a resistance that is lower than that of the drift layer;
• a cathode layer of the first conductivity-type formed on a surface layer of a second principal surface of the semiconductor substrate and contacting the drift layer;
• and a vacancy-oxygen complex defect region formed of complex defects of vacancies and oxygen, where the vacancy-oxygen complex defect region has a depth R in a direction from a boundary surface between the cathode layer and the drift layer toward a first principal surface of the semiconductor substrate, and the vacancy-oxygen complex defect region is provided at the depth R represented by 0<R≦t−W, where resistivity of the semiconductor substrate is ρ, thickness from a pn junction between the anode layer and the drift layer to the cathode layer is t, and width of a depletion layer extending in the drift layer from the pn junction with a reverse bias voltage V applied to the pn junction is W and represented by 0.54×√(ρ×V), the method comprising:
• forming the vacancy-oxygen complex defect region by:
• locally forming a high-concentration oxygen region comprising oxygen having a high-concentration, at a predetermined position, by ion implantation of oxygen;
• and
• subsequently shortening carrier lifetime by heavy metal diffusion.