Method for manufacturing semiconductor device having super junction construction
First Claim
1. A method for manufacturing a semiconductor device, comprising the steps of:
- forming a plurality of second parts having a second conductive type, wherein each second part is disposed separately;
forming a plurality of first parts having a first conductive type, wherein each first part is disposed between the second parts so that a drift region including the first and second parts aligned alternately in a repeat direction is provided;
forming a body region having the first conductive type on the drift region;
forming a trench, which penetrates the body region and reaches the drift region, wherein the trench extends in parallel to the repeat direction;
forming an insulation film on an inner wall of the trench;
embedding a gate electrode in the trench through the insulation film; and
reducing an impurity concentration of a portion of the first part of the drift region so that the impurity concentration of the portion is equal to or lower than that of the body region, wherein the portion of the first part is disposed near the trench.
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Abstract
A semiconductor device includes a body region, a drift region having a first part and a second part, and a trench gate electrode. The body region is disposed on the drift region. The first and second parts extend in an extending direction so that the second part is adjacent to the first part. The trench gate electrode penetrates the body region and reaches the drift region so that the trench gate electrode faces the body region and the drift region through an insulation layer. The trench gate electrode extends in a direction crossing with the extending direction of the first and second parts. The first part includes a portion near the trench gate electrode, which has an impurity concentration equal to or lower than that of the body region.
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Citations
17 Claims
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1. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a plurality of second parts having a second conductive type, wherein each second part is disposed separately; forming a plurality of first parts having a first conductive type, wherein each first part is disposed between the second parts so that a drift region including the first and second parts aligned alternately in a repeat direction is provided; forming a body region having the first conductive type on the drift region; forming a trench, which penetrates the body region and reaches the drift region, wherein the trench extends in parallel to the repeat direction; forming an insulation film on an inner wall of the trench; embedding a gate electrode in the trench through the insulation film; and reducing an impurity concentration of a portion of the first part of the drift region so that the impurity concentration of the portion is equal to or lower than that of the body region, wherein the portion of the first part is disposed near the trench. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a plurality of second parts having a second conductive type, wherein each second part is disposed separately;
forming a plurality of first parts having a first conductive type,wherein each first part is disposed between the second parts so that an under drift region including the first and second parts aligned alternately in a repeat direction is provided;
forming a semiconductor layer on the under drift region,wherein the semiconductor layer has the first conductive type and an impurity concentration of the semiconductor layer is equal to or lower than that of the first part of the under drift region; and doping an impurity having the second conductive type into a part of the semiconductor layer so that the part of the semiconductor layer changes its conductive type from the first conductive type to the second conductive type, wherein the part of the semiconductor layer is disposed on the second part. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification