Power semiconductor device and method of manufacturing the same

A method of manufacturing a power semiconductor device, the method comprising:

• preparing a base substrate having one surface and the other surface and formed of a first conductive type drift layer;
• forming an etching resist on one surface of the base substrate, the etching resist having an open part for forming a trench;
• forming a primary trench corresponding to the open part from one surface of the base substrate in a thickness direction;
• performing ion injection and thermal diffusion on the primary trench to form a first conductive type diffusion layer having a concentration higher than that of the first conductive type drift layer;
• and
• forming a secondary trench extended from a lower surface of the primary trench to the thickness direction and penetrating through the first conductive type diffusion layer,
• wherein a peak point of an impurity doping profile of the first conductive type diffusion layer according to the ion injection is positioned between one surface of the base substrate and a lower surface of the secondary trench.