Semiconductor device and semiconductor device manufacturing method

A semiconductor device comprising:

• a semiconductor base having one main surface and the other main surface,
• wherein the semiconductor base is divided into:
• a transistor region configuring a transistor from the one main surface to the other main surface;
• a diode region configuring a diode from the one main surface to the other main surface;
• and
• a device isolation region provided between the transistor region and the diode region that extend from the one main surface to the other main surface,
• the semiconductor base includes a drift layer of a first conductivity type in the transistor region, the diode region, and the device isolation region,
• the semiconductor base includes, in the transistor region:
• a base layer of a second conductivity type formed on the drift layer;
• a diffusion layer of the second conductivity type and an emitter layer of the first conductivity type formed selectively on the base layer, the diffusion layer having a higher second conductivity type impurity concentration than the base layer;
• and
• a gate electrode facing the base layer via an insulating film,
• the semiconductor base includes, in the diode region, an anode layer of the second conductivity type formed on the drift layer, and
• the semiconductor base includes no diffusion layer in the device isolation region.