A semiconductor device, comprising:
- a main semiconductor region through which a main current flows during an on-state of the device, the main semiconductor region being configured by a first structure;
- and
- a current detecting region having an active region through which another current different from the main current flows during the on-state, the current detecting region being configured by a second structure, wherein
- each of the first structure and the second structure has:
- a semiconductor substrate of a first conductivity type, the semiconductor substrate having a first main surface and a second main surface that are opposite to each other;
- a first semiconductor layer of the first conductivity type, provided at the first main surface of the semiconductor substrate, the first semiconductor layer having an impurity concentration that is lower than an impurity concentration of the semiconductor substrate, the first semiconductor layer having a first surface and a second surface that are opposite to each other, the second surface facing the semiconductor substrate;
- a second semiconductor layer of a second conductivity type, provided at the first surface of the first semiconductor layer, the second semiconductor layer having a first surface and a second surface that are opposite to each other, the second surface facing the semiconductor substrate;
- a plurality of first semiconductor regions of the second conductivity type, selectively provided in the second semiconductor layer, at the first surface of the second semiconductor layer, each of the plurality of first semiconductor regions having an impurity concentration that is higher than an impurity concentration of the second semiconductor layer;
- a plurality of trenches extending through the second semiconductor layer and reaching the first semiconductor layer;
- a plurality of gate electrodes respectively provided in the plurality of trenches via respective ones of a plurality of insulating films;
- a plurality of first high-concentration regions of the second conductivity type, provided in the first semiconductor layer and facing respective ones of the plurality of trenches in a depth direction of the device;
- a plurality of second high-concentration regions of the second conductivity type, each provided between an adjacent two of the plurality of trenches in the first semiconductor layer and the second semiconductor layer and connected to the plurality of first semiconductor regions;
- a plurality of first electrodes electrically connected to the second semiconductor layer;
- and
- a second electrode provided at the second main surface of the semiconductor substrate,
- the first structure further has a plurality of second semiconductor regions of the first conductivity type selectively provided in the second semiconductor layer, at the first surface of the second semiconductor layer, the plurality of trenches further respectively extending through the plurality of second semiconductor regions, each of the plurality of first electrodes being further electrically connected to a corresponding one of the plurality of second semiconductor regions, and
- the active region of the current detecting region has four corners, and includes:
- a first cell region operating as a transistor, and
- a plurality of second cell regions provided at respective ones of the four corners of the active region, and each operating as only a diode and not the transistor.