Trench-gate RESURF semiconductor device and manufacturing method
First Claim
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1. A trench-gate semiconductor device, comprising:
- a drain contact;
a silicon semiconductor body over the drain contact which is doped with a first type of dopant;
a gate trench formed in a top portion of the semiconductor body;
a gate dielectric lining the gate trench;
a gate electrode formed in the gate trench;
source regions formed in the semiconductor body on opposite sides of the gate trench, separated from the gate electrode by the gate dielectric; and
an implant well on each side of the gate trench, doped with a second type of dopant, of opposite polarity type to the first type of dopant of the semiconductor body, and extending more deeply into the semiconductor body than the gate trench,wherein the device further comprisesa pillar region extending downwardly from a bottom of the gate trench and which is electrically connected to the source regions, doped with the second type of dopant beneath the gate trench between the implant wells, andan additional implant well connected to the source regions and to the pillar region and configured and arranged to bias the pillar region at a potential of the source regions.
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Abstract
A trench-gate device with lateral RESURF pillars has an additional implant beneath the gate trench. The additional implant reduces the effective width of the semiconductor drift region between the RESURF pillars, and this provides additional gate shielding which improves the electrical characteristics of the device.
29 Citations
12 Claims
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1. A trench-gate semiconductor device, comprising:
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a drain contact; a silicon semiconductor body over the drain contact which is doped with a first type of dopant; a gate trench formed in a top portion of the semiconductor body; a gate dielectric lining the gate trench; a gate electrode formed in the gate trench; source regions formed in the semiconductor body on opposite sides of the gate trench, separated from the gate electrode by the gate dielectric; and an implant well on each side of the gate trench, doped with a second type of dopant, of opposite polarity type to the first type of dopant of the semiconductor body, and extending more deeply into the semiconductor body than the gate trench, wherein the device further comprises a pillar region extending downwardly from a bottom of the gate trench and which is electrically connected to the source regions, doped with the second type of dopant beneath the gate trench between the implant wells, and an additional implant well connected to the source regions and to the pillar region and configured and arranged to bias the pillar region at a potential of the source regions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification