US 11,923,443 B2
Semiconductor device
Shoko Hanagata, Komatsu (JP)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION, Tokyo (JP)
Filed on Sep. 8, 2021, as Appl. No. 17/469,239.
Claims priority of application No. 2021-043773 (JP), filed on Mar. 17, 2021.
Prior Publication US 2022/0302287 A1, Sep. 22, 2022
Int. Cl. H01L 29/739 (2006.01); H01L 29/08 (2006.01); H01L 29/861 (2006.01)
CPC H01L 29/7397 (2013.01) [H01L 29/083 (2013.01); H01L 29/861 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A semiconductor device in which a plurality of IGBT regions and a plurality of diode regions are alternately set along a first direction, the semiconductor device comprising:
a first electrode;
a semiconductor portion provided on the first electrode, the semiconductor portion including:
a first conductivity type collector layer provided in the IGBT region and in contact with the first electrode;
a second conductivity type low-concentration cathode layer provided in the diode region and in contact with the first electrode;
a high-concentration cathode layer provided in the diode region, in contact with the first electrode, being of a second conductivity type, and having an impurity concentration higher than an impurity concentration of the low-concentration cathode layer;
a second conductivity type drift layer provided on the collector layer, on the low-concentration cathode layer, and on the high-concentration cathode layer;
a plurality of first conductivity type anode layers partially provided on the drift layer in the diode region;
a plurality of first conductivity type base layers partially provided on the drift layer in the IGBT region; and
a second conductivity type emitter layer provided on the base layer in the IGBT region,
when the diode region on a lower surface of the semiconductor portion is divided into three equal regions of a first peripheral region, a central region, and a second peripheral region along the first direction, an area ratio of the low-concentration cathode layer in the central region being higher than the area ratio of the low-concentration cathode layer in the first peripheral region and the second peripheral region;
a second electrode provided on the semiconductor portion in the IGBT region and the diode region and connected to the anode layer and the emitter layer;
a third electrode provided in the IGBT region and facing the emitter layer, the base layer, and the drift layer; and
an insulating film provided between the semiconductor portion and the third electrode.