Semiconductor device and manufacturing method

A semiconductor device, comprising:

• a semiconductor substrate having a transistor region and a diode region spaced from the transistor region;
• a first electrode on a first side of the semiconductor substrate;
• a second electrode on a second side of the semiconductor substrate;
• and
• a plurality of gate electrodes in the semiconductor substrate between the first and second electrodes in a first direction, each gate electrode being surrounded by a gate insulating film, wherein
• the semiconductor substrate includes:
• a first semiconductor region on the first electrode;
• a second semiconductor region on the first semiconductor region and between adjacent pairs of gate electrodes in the plurality of gate electrodes;
• a third semiconductor region in the transistor region on the second semiconductor region;
• and
• a defect region, the defect region having a higher crystal defect density than a crystal defect density of the semiconductor substrate outside the defect region, and
• the defect region is in the second semiconductor region in the transistor region and the first semiconductor region in the diode region, a depth of the defect region being different in the transistor region and the diode region.

A manufacturing method for a semiconductor device, the manufacturing method comprising:

• preparing a semiconductor substrate having a transistor region and a diode region, the semiconductor substrate including a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type, the second semiconductor region being provided on the first semiconductor region, a third semiconductor region of the first conductivity type, the third semiconductor region being provided on the second semiconductor region in the transistor region, and a plurality of gate electrodes facing the second semiconductor region with a gate insulating portion interposed therebetween;
• forming an upper electrode on the semiconductor substrate;
• forming a resist on the upper electrode, the resist having an opening above the second semiconductor region in the diode region;
• selectively removing an upper portion of the upper electrode so as to form a first upper surface in the transistor region and a second upper surface in the diode region, the second upper surface being formed closer to the semiconductor substrate than the first upper surface;
• and
• implanting a dopant into the semiconductor substrate through the upper electrode so as to form a defect region in the semiconductor substrate, the defect region having a higher crystal defect density than a crystal defect density of the semiconductor substrate outside the defect region.