| CPC H10D 30/668 (2025.01) [H10D 30/0297 (2025.01); H10D 62/127 (2025.01); H10D 64/513 (2025.01)] | 7 Claims |
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1. A semiconductor device comprising:
a cell portion including a main cell region and a sense cell region, the cell portion having a semiconductor element in each of the main cell region and the sense cell region, the main cell region having a structure identical to the sense cell region, the sense cell region configured to enable a flow of a smaller current than the main cell region; and
a peripheral portion surrounding the cell portion, wherein
the semiconductor element in each of the main cell region and the sense cell region includes:
a semiconductor substrate being a first conductivity type and having a drift layer;
a first impurity region located on the drift layer and being a second conductivity type;
a second impurity region located on a surface layer portion of the first impurity region, the second impurity region being a first conductivity type and having a higher impurity concentration than the drift layer;
a plurality of trench-gate structures arranged in a stripe shape, each of the plurality of trench-gate structures including a gate trench, a shield electrode, an intermediate insulating film, a gate electrode, and an insulating film, the gate trench having one direction as a longitudinal direction of the gate trench while penetrating the first impurity region from the second impurity region and reaching the drift layer, each of the plurality of trench-gate structures configured to have double gates by stacking the shield electrode, the intermediate insulating film and the gate electrode in order via the insulating film in the gate trench;
a contact trench located between adjacent two of the plurality of trench-gate structures, the contact trench having the one direction as a longitudinal direction of the contact trench, the contact trench extending from the cell portion to the peripheral portion while penetrating the second impurity region and reaching the first impurity region;
a contact region configured for the second impurity region, the contact region located along a wall surface of the contact trench, the contact region having a higher impurity concentration than the second impurity region;
a high-concentration layer being the first conductivity type or the second conductivity type, the high-concentration layer located on a side opposite from the first impurity region with the drift layer sandwiched between the first impurity region and the high-concentration layer;
an interlayer insulating film having a contact hole communicating with the contact trench, the interlayer insulating film located on the first impurity region, the second impurity region, and the plurality of trench-gate structures;
a first electrode electrically connected to the contact region and the first impurity region through the contact hole and the contact trench; and
a second electrode electrically connected to the high-concentration layer,
a length of the cell portion in the one direction is identical to a length of the second impurity region in the one direction,
the contact region extends from the cell portion to the peripheral portion,
a length of a section of the contact region located at the peripheral portion in the one direction is defined as a protruding length, and the length of the second impurity region in the one direction is defined as a second-impurity-region length, and
a ratio of the protruding length to the second-impurity-region length is 0.1 or smaller.
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