Semiconductor device, semiconductor device manufacturing method, and power converter

A semiconductor device comprising:

• a semiconductor substrate in which a cell region, an isolation region, and a termination region are defined, the cell region being an active region where a current flows, the isolation region being a region which is located outward of the cell region and where generation of an electric field is limited when a breakdown voltage is held, the termination region including a guard ring region and an excess region, the guard ring region being located outward of the isolation region, the excess region being a region which is located outward of the guard ring region and where development of a depletion layer is limited when the breakdown voltage is held;
• an insulating layer covering a top surface of the semiconductor substrate in the isolation region and the termination region;
• a surface electrode located on a portion of the top surface of the semiconductor substrate and a portion of a top surface of the insulating layer in the cell region and the isolation region;
• and
• a waterproof layer covering a portion of the insulating layer exposed from the surface electrode, wherein
• the waterproof layer is spaced apart from the surface electrode.