Semiconductor device

1. A semiconductor device including an IGBT and a diode, the semiconductor device comprising:

a semiconductor substrate;

an upper electrode covering an upper surface of the semiconductor substrate; and

a lower electrode covering a lower surface of the semiconductor substrate;

wherein

the semiconductor substrate comprises:

a body region of a p-type being in contact with the upper electrode;

a drift region of an n-type located on a lower side of the body region;

a cathode region of the n-type located in a part of a range on a lower side of the drift region, being in contact with the lower electrode, and having an n-type impurity concentration higher than the drift region; and

a collector region of the p-type located in another part of the range on the lower side of the drift region, and being in contact with the lower electrode at a position bordering the cathode region,

wherein

a plurality of trenches is provided on the upper surface of the semiconductor substrate, the plurality of trenches penetrating the body region and reaching the drift region,

a trench electrode insulated from the semiconductor substrate and the upper electrode by an insulating film is located in each of the trenches,

the semiconductor substrate comprises a plurality of inter-trench semiconductor regions, each of the inter-trench semiconductor regions being intervened between the adjacent trenches,

the plurality of inter-trench semiconductor regions comprises a plurality of first inter-trench semiconductor regions adjacent to each other and a plurality of second inter-trench semiconductor regions adjacent to each other,

each of the first inter-trench semiconductor regions comprises an emitter region of the n-type being in contact with the upper electrode and the insulating film and separated from the drift region by the body region,

each of the second inter-trench semiconductor regions does not comprise the emitter region,

a range in which the plurality of first inter-trench semiconductor regions is located in a plan view of the semiconductor substrate is an IGBT area, and a range in which the plurality of second inter-trench semiconductor regions is located in the plan view of the semiconductor substrate is a diode area,

at least a part of the collector region is located in the IGBT area,

at least a part of the cathode region is located in the diode area,

a border between the cathode region and the collector region is located in a range directly below a border trench and two of the inter-trench semiconductor regions bordering the border trench, the border trench being one of the trenches that is located at a border between the IGBT area and the diode area,

an upper-side lifetime control region is provided in the diode area and is not provided in the IGBT area, the upper-side lifetime control region being a region extending along a planar direction in the drift region within a range located above an intermediate depth of the drift region, and the upper-side lifetime control region having a crystal defect density higher than the drift region surrounding the upper-side lifetime control region,

one of the first inter-trench semiconductor regions that is adjacent to the second inter-trench semiconductor regions is a border first inter-trench semiconductor region,

the border first inter-trench semiconductor region comprises:

a barrier region of the n-type located between the body region and the drift region and having an n-type impurity concentration higher than the drift region; and

a pillar region of the n-type extending from a position being in contact with the upper electrode to a position being in contact with the barrier region, and

each of the second inter-trench semiconductor regions does not comprise the pillar region.

2. The semiconductor device of claim 1 , wherein

a lower body region of the p-type is located between the barrier region and the drift region, and

each of the first inter-trench semiconductor regions other than the border first inter-trench semiconductor region does not comprise the barrier region and the pillar region.

3. The semiconductor device of claim 1 , wherein the border between the cathode region and the collector region is located in a range directly below the border trench.