Dual channel trench LDMOS transistors with drain superjunction structure integrated therewith
First Claim
1. A semiconductor device comprising a dual channel trench LDMOS transistor, the dual channel trench LDMOS transistor comprising:
- a semiconductor layer of a first conductivity type formed on a substrate;
a first trench formed in the semiconductor layer, the first trench being filled with a trench dielectric, a trench gate being formed in the first trench and insulated from the sidewall of the first trench by a first gate dielectric layer, the trench gate forming a vertical channel of the LDMOS transistor;
a body region of a second conductivity type formed in the semiconductor layer adjacent the first trench;
a source region of the first conductivity type formed in the body region and adjacent the first trench;
a planar gate insulated from the semiconductor layer by a second gate dielectric layer and overlying the body region, the source region being formed aligned to a first edge of the planar gate, the planar gate forming a lateral channel of the LDMOS transistor;
a drain drift region of the first conductivity type formed in the semiconductor layer and in electrical contact with a drain electrode; and
a plurality of alternating N-type and P-type regions formed in the drain drift region, the plurality of alternating N-type and P-type regions having higher doping concentration than the drain-drift regions and forming a super-junction structure in the drain drift region.
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Abstract
A dual channel trench LDMOS transistor includes a semiconductor layer of a first conductivity type formed on a substrate; a first trench formed in the semiconductor layer where a trench gate is formed in an upper portion of the first trench; a body region of the second conductivity type formed in the semiconductor layer adjacent the first trench; a source region of the first conductivity type formed in the body region and adjacent the first trench; a planar gate overlying the body region; a drain drift region of the first conductivity type formed in the semiconductor layer and in electrical contact with a drain electrode; and alternating N-type and P-type regions formed in the drain drift region with higher doping concentration than the drain-drift regions to form a super-junction structure in the drain drift region.
23 Citations
22 Claims
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1. A semiconductor device comprising a dual channel trench LDMOS transistor, the dual channel trench LDMOS transistor comprising:
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a semiconductor layer of a first conductivity type formed on a substrate; a first trench formed in the semiconductor layer, the first trench being filled with a trench dielectric, a trench gate being formed in the first trench and insulated from the sidewall of the first trench by a first gate dielectric layer, the trench gate forming a vertical channel of the LDMOS transistor; a body region of a second conductivity type formed in the semiconductor layer adjacent the first trench; a source region of the first conductivity type formed in the body region and adjacent the first trench; a planar gate insulated from the semiconductor layer by a second gate dielectric layer and overlying the body region, the source region being formed aligned to a first edge of the planar gate, the planar gate forming a lateral channel of the LDMOS transistor; a drain drift region of the first conductivity type formed in the semiconductor layer and in electrical contact with a drain electrode; and a plurality of alternating N-type and P-type regions formed in the drain drift region, the plurality of alternating N-type and P-type regions having higher doping concentration than the drain-drift regions and forming a super-junction structure in the drain drift region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification