Trench MOSFET device and the preparation method thereof
First Claim
1. A method for fabricating a trench metal-oxide-semiconductor field-effect transistor (MOSFET) device, the method comprising the steps of:
- providing a semiconductor substrate of a first conductivity type;
forming a plurality of first trenches arranged side by side in a first stripe layout extending along a first direction in a first preset area of the semiconductor substrate;
forming a plurality of second trenches arranged side by side in a second stripe layout extending along a second direction perpendicular to the first direction in a second preset area of the semiconductor substrate;
filling the plurality of first trenches and the plurality of second trenches with a conductive material so as to form a plurality of control gates;
implanting dopant of a second conductivity type on a top portion of the semiconductor substrate to form a body region; and
implanting dopant of the first conductivity type on a top portion of the body region to form a source region;
before the step of filling the plurality of first trenches and the plurality of second trenches with the conductive material,covering a first insulation layer over a bottom surface and sidewalls of each of the plurality of first trenches and the plurality of second trenches;
wherein the step of filling the plurality of first trenches and the plurality of second trenches with the conductive material so as to form the plurality of control gates comprises;
depositing the conductive material on the semiconductor substrate so the plurality of first trenches and the plurality of second trenches are filled with the conductive material; and
etching away an excessive portion of the conductive material so that the plurality of control gates are formed from a remaining portion of the conductive material in the plurality of first trenches and the plurality of second trenches;
after the step of implanting dopant of the first conductivity type on the top portion of the body region to form the source region,forming a passivation layer on the plurality of control gate in the plurality of first trenches and the plurality of second trenches and on the semiconductor substrate;
etching the passivation layer to form a plurality of stripe contact trenches penetrating the passivation layer, the source region and an upper portion of the body region; and
filling the plurality of stripe contact trenches with another metal material;
wherein the stripe contact trenches are formed between adjacent first trenches of the plurality of first trenches and between adjacent second trenches of the plurality of second trenches.
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Accused Products
Abstract
A trench-type metal-oxide-semiconductor field-effect transistor (MOSFET) device and a fabrication method are disclosed. A semiconductor substrate of a first conductivity type is provided. A plurality of first trenches arranged side by side in a first stripe layout extending along a first direction in a first preset area of the semiconductor substrate are formed. A plurality of second trenches arranged side by side in a second stripe layout extending along a second direction perpendicular to the first direction in a second preset area of the semiconductor substrate are formed. The plurality of first trenches and the plurality of second trenches are filled with a conductive material so as to form a plurality of control gates.
20 Citations
6 Claims
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1. A method for fabricating a trench metal-oxide-semiconductor field-effect transistor (MOSFET) device, the method comprising the steps of:
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providing a semiconductor substrate of a first conductivity type; forming a plurality of first trenches arranged side by side in a first stripe layout extending along a first direction in a first preset area of the semiconductor substrate; forming a plurality of second trenches arranged side by side in a second stripe layout extending along a second direction perpendicular to the first direction in a second preset area of the semiconductor substrate; filling the plurality of first trenches and the plurality of second trenches with a conductive material so as to form a plurality of control gates; implanting dopant of a second conductivity type on a top portion of the semiconductor substrate to form a body region; and implanting dopant of the first conductivity type on a top portion of the body region to form a source region; before the step of filling the plurality of first trenches and the plurality of second trenches with the conductive material, covering a first insulation layer over a bottom surface and sidewalls of each of the plurality of first trenches and the plurality of second trenches; wherein the step of filling the plurality of first trenches and the plurality of second trenches with the conductive material so as to form the plurality of control gates comprises; depositing the conductive material on the semiconductor substrate so the plurality of first trenches and the plurality of second trenches are filled with the conductive material; and etching away an excessive portion of the conductive material so that the plurality of control gates are formed from a remaining portion of the conductive material in the plurality of first trenches and the plurality of second trenches; after the step of implanting dopant of the first conductivity type on the top portion of the body region to form the source region, forming a passivation layer on the plurality of control gate in the plurality of first trenches and the plurality of second trenches and on the semiconductor substrate; etching the passivation layer to form a plurality of stripe contact trenches penetrating the passivation layer, the source region and an upper portion of the body region; and filling the plurality of stripe contact trenches with another metal material; wherein the stripe contact trenches are formed between adjacent first trenches of the plurality of first trenches and between adjacent second trenches of the plurality of second trenches. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification