Semiconductor device including emitter regions and method of manufacturing the semiconductor device

A semiconductor device, comprising:

• a first conductive-type semiconductor layer;
• a gate trench and an emitter trench that are formed in the first conductive-type semiconductor layer;
• a gate electrode that is embedded in the gate trench;
• an embedding electrode that is embedded in the emitter trench;
• a second conductive-type base region that is formed in a front surface portion of the first conductive-type semiconductor layer between the gate trench and the emitter trench;
• a first conductive-type emitter region that is formed in a front surface portion of the second conductive-type base region;
• a first embedding insulating film that is embedded in the gate trench on the gate electrode and that has an upper surface in the same height position as a front surface of the first conductive-type semiconductor layer or in a height position lower than the front surface of the first conductive-type semiconductor layer;
• a second embedding insulating film that is embedded in the emitter trench on the embedded electrode and that has an upper surface in the same height position as the front surface of the first conductive-type semiconductor layer or in a height position lower than the front surface of the first conductive-type semiconductor layer;
• and
• an emitter electrode that covers the first and second embedding insulating films and that are electrically connected to the second conductive-type base region and the first conductive-type emitter region;
• and
• a surface insulating film formed on the first conductive-type semiconductor layer, wherein
• a contact hole is formed in the surface insulating film,
• an entire upper surface of the first embedding insulating film faces inside the contact hole and forms a part of a bottom portion of the contact hole, and
• a part of an upper surface of the second embedding insulating film faces inside the contact hole and forms another part of the bottom portion of the contact hole.