Semiconductor power device and method for producing same

A wide bandgap semiconductor device, comprising:

• a semiconductor substrate having a first conductivity type;
• a gate trench formed in the semiconductor substrate;
• a gate insulating film formed on a side of the gate trench and a bottom surface of the gate trench, and partly covering a surface of the semiconductor substrate;
• a gate electrode buried in the gate trench;
• an interlayer insulating film stacked on the semiconductor substrate such that the gate electrode is covered with the interlayer insulating film;
• an intermediate layer disposed over the semiconductor substrate and the interlayer insulating film;
• a metal layer disposed on or over the intermediate layer;
• a first source region having the first conductivity type and a first body region having a second conductivity type disposed along the side of the gate trench, in order from a surface of the semiconductor substrate to a reverse surface of the semiconductor substrate;
• a body contact region electrically connected to the first body region in a cross sectional view;
• a diode region disposed lower than the first body region in a cross sectional view;
• and
• a drain electrode formed on the reverse surface of the semiconductor substrate, the drain electrode including at least Ti and Ni, wherein
• a pn-diode having a pn-junction is disposed in the diode region such that the pn-junction is lower than the bottom surface of the gate trench, and
• a width of the diode region is wider than a width of the first body region.