Silicon carbide semiconductor device
AssigneeSumitomo Electric Industries, Ltd.
InventorsTakeyoshi Masuda, Ryouji Kosugi
Life of this patent
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Abstract
A super junction layer alternately has a first region and a second region. An element layer is provided above the super junction layer. The first region has a first portion and a second portion located between the first portion and a first main surface. The second region has a third portion in contact with the first portion and a fourth portion in contact with the second portion and located between the third portion and the first main surface. In a cross section perpendicular to the second main surface and parallel to a direction from the first region toward the second region, a width of the second portion is larger than a width of the first portion, a width of the fourth portion is smaller than a width of the third portion.
Claims11
A silicon carbide semiconductor device comprising:
- a substrate composed of a silicon carbide semiconductor having a first conductivity type;
- a super junction layer that is provided above a first main surface of the substrate and that alternately has a first region having the first conductivity type and a second region having a second conductivity type;
- an element layer provided above the super junction layer, the element layer comprising a first impurity region having the first conductivity type;
- a first electrode provided on the element layer;
- and
- a second electrode provided on a second main surface of the substrate opposite to the first main surface, wherein
- the element layer is provided with a trench that has a bottom portion constituted of the first impurity region,
- a gate electrode is provided inside the trench,
- a connection region having the second conductivity type is in contact with the second region and the first impurity region,
- the first impurity region separates the gate electrode from the connection region, the first region has a first portion and a second portion located between the first portion and the first main surface,
- the second region has a third portion in contact with the first portion and a fourth portion in contact with the second portion and located between the third portion and the first main surface, and
- in a cross section perpendicular to the second main surface and parallel to a direction from the first region toward the second region,
- a width of the second portion is larger than a width of the first portion and is monotonously increased in a direction from the first portion toward the first main surface,
- a width of the fourth portion is smaller than a width of the third portion and is monotonously decreased in a direction from the third portion toward the first main surface,
- a total value of the width of the first portion and the width of the third portion is 0.5 μm or more and 4 μm or less, and
- a height of each of the first region and the second region is 2 μm or more.
A silicon carbide semiconductor device, comprising:
- a substrate composed of a silicon carbide semiconductor having a first conductivity type;
- a super junction layer that is provided above a first main surface of the substrate and that alternately has a plurality of first regions having the first conductivity type and a plurality of second regions having a second conductivity type, the first regions being stacked together, the second regions being stacked together;
- an element layer provided above the super junction layer;
- a first electrode provided on the element layer;
- and
- a second electrode provided on a second main surface of the substrate opposite to the first main surface, wherein
- wherein each of the first regions has a first portion and a second portion located between the first portion and the first main surface,
- wherein each of the second regions has a third portion and a fourth portion, the third portion being in contact with the first portion, and the fourth portion being in contact with the second portion and located between the third portion and the first main surface, and
- wherein, in a cross section perpendicular to the second main surface and parallel to a direction from the first regions toward the second regions,
- a width of the second portion is larger than a width of the first portion and is monotonously increased in a direction from the first portion toward the first main surface,
- a width of the fourth portion is smaller than a width of the third portion and is monotonously decreased in a direction from the third portion toward the first main surface,
- a total value of the width of the first portion and the width of the third portion is 0.5 μm or more and 4 μm or less, and
- a height of each of the first regions and each of the second regions is 2 μm or more.
Dependencies are inferred from the claim text.