FABRICATION METHOD OF TRENCHED POWER SEMICONDUCTOR DEVICE WITH SOURCE TRENCH
First Claim
1. a fabrication method of a trenched power semiconductor device with a source trench, comprising the steps of:
- providing a base;
forming at least two gate trenches in the base;
forming a first dielectric layer to line the inner surfaces of the gate trenches;
forming a first polysilicon structure in the gate trenches lining with the first dielectric layer;
forming at least a source trench between the two neighboring gate trenches;
forming a second dielectric layer to line the inner surfaces of the source trench;
forming a second polysilicon structure in a lower portion of the source trench lining with the second dielectric layer;
forming a body region between the gate trenches, wherein the depth of the source trench is greater than the depth of the body region;
forming a source region between the gate trenches;
removing a portion of the second dielectric layer to expose the source region and the body region; and
filling a conductive structure in the source trench for electrically connecting the second polysilicon structure, the body region, and the source region.
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Accused Products
Abstract
A fabrication method of a trenched power semiconductor device with source trench is provided. Firstly, at least two gate trenches are formed in a base. Then, a dielectric layer and a polysilicon structure are sequentially formed in the gate trench. Afterward, at least a source trench is formed between the neighboring gate trenches. Next, the dielectric layer and a second polysilicon structure are sequentially formed in the source trench. The second polysilicon structure is located in a lower portion of the source trench. Then, the exposed portion of the dielectric layer in the source trench is removed to expose a source region and a body region. Finally, a conductive structure is filled into the source trench to electrically connect the second polysilicon structure, the body region, and the source region.
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Citations
16 Claims
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1. a fabrication method of a trenched power semiconductor device with a source trench, comprising the steps of:
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providing a base; forming at least two gate trenches in the base; forming a first dielectric layer to line the inner surfaces of the gate trenches; forming a first polysilicon structure in the gate trenches lining with the first dielectric layer; forming at least a source trench between the two neighboring gate trenches; forming a second dielectric layer to line the inner surfaces of the source trench; forming a second polysilicon structure in a lower portion of the source trench lining with the second dielectric layer; forming a body region between the gate trenches, wherein the depth of the source trench is greater than the depth of the body region; forming a source region between the gate trenches; removing a portion of the second dielectric layer to expose the source region and the body region; and filling a conductive structure in the source trench for electrically connecting the second polysilicon structure, the body region, and the source region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification