SEMICONDUCTOR DEVICE
First Claim
1. A semiconductor device, comprising:
- a semiconductor substrate;
a plurality of first semiconductor regions of a first conduction type formed by disposing a single crystal semiconductor layer of the first conduction type on a surface of the semiconductor substrate and providing a plurality of trenches in the single crystal semiconductor layer, the trenches each having a bottom and sides, a width between the sides being larger as becoming more distant from the bottom, and the plurality of first semiconductor regions being formed at intervals in a direction parallel to the surface; and
a plurality of second semiconductor regions of a second conduction type formed of an epitaxial layer buried in the plurality of trenches,the plurality of first semiconductor regions having impurity concentrations controlled to increase as becoming more distant from the surface.
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Accused Products
Abstract
A single crystal semiconductor layer of a first conduction type is disposed on a surface of a semiconductor substrate. A plurality of trenches are provided in the semiconductor layer to form a plurality of first semiconductor regions of the first conduction type at intervals in a direction parallel to the surface. An epitaxial layer is buried in the plurality of trenches to form a plurality of second semiconductor regions of a second conduction type. The plurality of second semiconductor regions each includes an outer portion with a high impurity concentration formed against an inner wall of the trench, and an inner portion with a low impurity concentration formed inner than the outer portion.
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Citations
7 Claims
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1. A semiconductor device, comprising:
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a semiconductor substrate; a plurality of first semiconductor regions of a first conduction type formed by disposing a single crystal semiconductor layer of the first conduction type on a surface of the semiconductor substrate and providing a plurality of trenches in the single crystal semiconductor layer, the trenches each having a bottom and sides, a width between the sides being larger as becoming more distant from the bottom, and the plurality of first semiconductor regions being formed at intervals in a direction parallel to the surface; and a plurality of second semiconductor regions of a second conduction type formed of an epitaxial layer buried in the plurality of trenches, the plurality of first semiconductor regions having impurity concentrations controlled to increase as becoming more distant from the surface. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification