Power semiconductor device

A power semiconductor device comprising:

• a semiconductor layer having a surface, said semiconductor layer being formed of sic;
• a semiconductor region of a predetermined conductivity type, said semiconductor region being formed in said semiconductor layer so as to be exposed at least at a portion of said surface of said semiconductor layer;
• a first insulation film formed on said semiconductor region;
• an electrode formed on said semiconductor region or on said first insulation film;
• a first metal layer formed on said electrode and containing at least one selected from the group consisting of Pt, Ti, Mo, W and Ta;
• and
• a second metal layer formed on said first metal layer and containing at least one selected from the group consisting of Mo, W and Cu.

A power semiconductor device comprising:

• a semiconductor layer having a surface;
• a semiconductor region of a predetermined conductivity type, said semiconductor region being formed in said semiconductor layer so as to be exposed at least at a portion of said surface of said semiconductor layer;
• a first insulation film formed on said semiconductor region;
• an electrode formed on said semiconductor region or on said first insulation film;
• a first metal layer formed on said electrode and containing at least one selected from the group consisting of Pt, Ti, Mo, W and Ta;
• a second metal layer formed on said first metal layer and containing at least one selected from the group consisting of Mo, W and Cu;
• and
• a third metal layer formed on said second metal layer and containing at least one selected from the group consisting of Pt, Mo and W.

A power semiconductor device comprising:

• a semiconductor layer having a surface;
• a semiconductor region of a predetermined conductivity type, said semiconductor region being formed in said semiconductor layer so as to be exposed at least at a portion of said surface of said semiconductor layer;
• a first insulation film formed on said semiconductor region;
• an electrode formed on said semiconductor region;
• a first metal layer formed on said electrode and containing at least one selected from the group consisting of Pt, Ti, Mo, W and Ta;
• a second metal layer formed on said first metal layer and containing at least one selected from the group consisting of Mo, W and Cu;
• and
• a second insulation film formed in a region which is on said surface of said semiconductor layer and/or on a surface of said first insulation film and which is other than a region where said electrode is formed, wherein
• said first and second metal layers extend over said second insulation film,
• said first metal layer is present between said electrode formed on said semiconductor region and said second insulation film so as to prevent said electrode and said second insulation film from contacting each other.