Method of manufacturing semiconductor device and semiconductor device

A semiconductor device comprising:

• a semiconductor substrate;
• trench portions, each of which is provided from an upper surface of the semiconductor substrate to an inside of the semiconductor substrate, and is provided to extend in a predetermined extension direction on the upper surface of the semiconductor substrate;
• a base region of a second conductivity type which is provided to be shallower than each of the trench portions inside the semiconductor substrate;
• a contact region of the second conductivity type which is provided above the base region inside the semiconductor substrate;
• an emitter region which is provided in alignment with the contact region above the base region inside the semiconductor substrate;
• a plug region of the second conductivity type which is provided to be shallower than a depth of the contact region inside the semiconductor substrate, and has a higher doping concentration than that of the contact region;
• and
• a contact hole which is provided above the contact region and the emitter region, and of which an opening width between the trench portions is smaller than a length of the contact region in the extension direction, wherein
• a cell formed by the contact region and the emitter region has a length, in the extension direction, which is smaller than or equal to a width between adjacent two of the trench portions, and the emitter region has a length, in the extension direction, which is greater than the length of the contact region, and
• a first integrated concentration obtained by integrating the doping concentration of the plug region in a depth direction of the semiconductor substrate is higher than or equal to a second integrated concentration obtained by integrating the doping concentration of the contact region in the depth direction of the semiconductor substrate.