Semiconductor device

A semiconductor device comprising:

• a semiconductor substrate having an IGBT region, a diode region, and a boundary region between the IGBT region and the diode region, the IGBT region having an upper surface on which one or more IGBT trenches are formed, the diode region having an upper surface on which no trench gate structure is formed;
• a front surface electrode provided on an upper surface of the semiconductor substrate;
• a back surface electrode provided on a back surface of the semiconductor substrate;
• and
• IGBT gate electrodes provided inside the respective IGBT trenches, wherein
• a plurality of boundary trenches are formed on an upper surface of the boundary region, and
• the plurality of boundary trenches satisfies one or more of the following:
• a trench closest to the diode region is shallower than a trench closest to the IGBT region;
• a trench closest to the diode region is narrower than a trench closest to the IGBT region;
• and
• a pitch of the boundary trenches is different from a pitch of the IGBT trenches.

A semiconductor device comprising:

• a semiconductor substrate having an IGBT region and a diode region, the IGBT region having an upper surface on which one or more IGBT trenches are formed, the diode region having an upper surface on which no trench gate structure is formed;
• a front surface electrode provided on an upper surface of the semiconductor substrate;
• a back surface electrode provided on a back surface of the semiconductor substrate;
• and
• IGBT gate electrodes provided inside the respective IGBT trenches, wherein
• an anode layer of the diode region is provided so as to cover a lower end of a trench provided closest to the diode region among the IGBT trenches.