Semiconductor device having alternately arranged IGBT regions and diode regions
A semiconductor device may have a semiconductor substrate. The semiconductor substrate may include an IGBT region that overlaps with a collector region and a diode region that overlaps with a cathode region. The semiconductor substrate may include a drift region distributed across the IGBT region and the diode region, a body region, a body contact region, and an emitter region arranged in the IGBT region, and an anode region and an anode contact region arranged in the diode region. The body region may include a first body region and a second body region having a p-type impurity density lower than any of that in the first body region and that in the anode region. The second body region may be adjacent to the anode region. The first body region may be adjacent to the second body region at an opposite side from the anode region.
1. A semiconductor device, comprising:
a semiconductor substrate;
a trench provided in an upper surface of the semiconductor substrate;
a gate insulating film provided in the trench;
a gate electrode provided in the trench and insulated from the semiconductor substrate by the gate insulating film;
an upper electrode being in contact with the upper surface; and
a lower electrode being in contact with a lower surface of the semiconductor substrate,
wherein
the semiconductor substrate comprises a collector region of p-type and a cathode region of n-type in a range being in contact with the lower electrode,
along a thickness direction of the semiconductor substrate, a semiconductor region overlapping with the collector region is an IGBT region and a semiconductor region overlapping with the cathode region is a diode region,
the trench is provided in the IGBT region,
the semiconductor substrate comprises:
a drift region of n-type distributed across the IGBT region and the diode region, provided above the collector region and the cathode region, and being in contact with the gate insulating film;
a body region of p-type, provided above the drift region in the IGBT region, and being in contact with the gate insulating film;
a body contact region of p-type, provided above the body region, having a p-type impurity density higher than a p-type impurity density in the body region, and being in contact with the upper electrode;
an emitter region of n-type, provided above the body region, being in contact with the upper electrode, being in contact with the gate insulating film, and separated from the drift region by the body region;
an anode region of p-type provided above the drift region in the diode region; and
an anode contact region of p-type, provided above the anode region, having a p-type impurity density higher than a p-type impurity density in the anode region, and being in contact with the upper electrode,
the body region comprises a first body region and a second body region having a p-type impurity density lower than any of a p-type impurity density in the first body region and the p-type impurity density in the anode region,
the second body region is adjacent to the anode region, and
the first body region is adjacent to the second body region at an opposite side from the anode region.
2. The semiconductor device of claim 1 , wherein the p-type impurity density in the second body region is distributed so as to decrease toward the anode region.
3. The semiconductor device of claim 2 , wherein the p-type impurity density in the second body region is distributed so as to continuously decrease toward the anode region.
4. The semiconductor device of claim 2 , wherein the p-type impurity density in the second body region is distributed so as to decrease in a stepwise manner toward the anode region.