BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device.

2. Description of the Related Art

FIG. 2 of US2010276727A1 discloses an RC-IGBT (Reverse Conducting-Insulated Gate Bipolar Transistor) serving as an example of a semiconductor device.

The RC-IGBT includes a semiconductor layer. A p type channel region is formed in a surface layer portion of a front surface of the semiconductor layer. An n type emitter region is formed in a surface layer portion of the channel region. A gate electrode electrically connected to the channel region across an insulating film is formed at the front surface of the semiconductor layer. A p type connector region and plural n type cathode regions are formed in a region of a surface layer portion of a rear surface of the semiconductor layer, the region facing the channel region.

SUMMARY OF THE INVENTION

One preferred embodiment of the present invention provides a semiconductor device that includes a semiconductor layer of a first conductivity type having a first principal surface on one side and a second principal surface on the other side, the semiconductor layer in which a device formation region and an outer region outside the device formation region are set, a channel region of a second conductivity type formed in a surface layer portion of the first principal surface of the semiconductor layer in the device formation region, an emitter region of a first conductivity type formed in a surface layer portion of the channel region, a gate electrode formed at the first principal surface of the semiconductor layer in the device formation region, the gate electrode facing the channel region across a gate insulating film, a collector region of a second conductivity type formed in a surface layer portion of the second principal surface of the semiconductor layer in the device formation region, an inner cathode region of a first conductivity type formed in the surface layer portion of the second principal surface of the semiconductor layer in the device formation region, and an outer cathode region of a first conductivity type formed in the surface layer portion of the second principal surface of the semiconductor layer in the outer region.

One preferred embodiment of the present invention provides a semiconductor layer of a first conductivity type having a first principal surface on one side and a second principal surface on the other side, a channel region of a second conductivity type formed in a surface layer portion of the first principal surface of the semiconductor layer, an emitter region of a first conductivity type formed in a surface layer portion of the channel region, a gate electrode formed at the first principal surface of the semiconductor layer, the gate electrode facing the channel region across a gate insulating film, a collector region of a second conductivity type formed in a facing region facing the channel region in a surface layer portion of the second principal surface of the semiconductor layer, an inner cathode region of a first conductivity type formed in the facing region in the surface layer portion of the second principal surface of the semiconductor layer, and an outer cathode region of a first conductivity type formed in a non-facing region which is a region outside the facing region in the surface layer portion of the second principal surface of the semiconductor layer.

The above and other objects, features, and effects of the present invention will be made clear by the following description of the preferred embodiments with reference to the accompanying drawings.

