| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problem that a p base ohmic contact of a silicon carbide semiconductor device is composed of a p++ layer formed by high concentration ion implantation and a metal electrode, however, if the high concentration ion implantation is performed at a room temperature, a crystal in the p++ layer is extremely damaged which causes a process defect, therefore a method of performing the implantation at a high temperature is applied, and from a viewpoint of a switching loss or the like of the device, it is preferable that p base ohmic contact resistivity is low, but in well-known technologies, detailed relation between the ion implantation temperature and the ohmic contact resistivity and/or the process defect is not mentioned.SOLUTION: In an ion implantation step, a temperature of a silicon carbide wafer is kept at 175 to 300°C, preferably, at 175 to 200°C. The p base ohmic contact resistivity using a p++ region formed by ion implantation at 175 to 300°C becomes lower than in a case where the ion implantation is performed at a temperature exceeding 300°C. Further, a process defect is also prevented from occurring.</p> |
