SEMICONDUCTOR DEVICE WITH IMPROVED ON-RESISTANCE
First Claim
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1. A method for manufacturing a semiconductor device, the method comprising:
- etching a trench into a doped semiconductor substrate including a drift zone and a drain region;
forming a first dielectric layer over the substrate;
providing positive charges over the first dielectric layer;
depositing a second dielectric layer over the positive charges;
depositing a hard mask material or conductive material in the trench;
recess etching the hard mask material or the conductive material to expose portions of the second dielectric layer within the trench;
etching the second dielectric layer, the positive charges, and the first dielectric layer to expose the sidewalls of the trench above the hard mask or the conductive material; and
forming a third dielectric layer over the hard mask or conductive material layer and the exposed sidewalls of the trench.
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Abstract
A semiconductor device includes a source, a drain, and a gate configured to selectively enable a current to pass between the source and the drain. The semiconductor device includes a drift zone between the source and the drain and a first field plate adjacent the drift zone. The semiconductor device includes a dielectric layer electrically isolating the first field plate from the drift zone and charges within the dielectric layer close to an interface of the dielectric layer adjacent the drift zone.
5 Citations
12 Claims
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1. A method for manufacturing a semiconductor device, the method comprising:
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etching a trench into a doped semiconductor substrate including a drift zone and a drain region; forming a first dielectric layer over the substrate; providing positive charges over the first dielectric layer; depositing a second dielectric layer over the positive charges; depositing a hard mask material or conductive material in the trench; recess etching the hard mask material or the conductive material to expose portions of the second dielectric layer within the trench; etching the second dielectric layer, the positive charges, and the first dielectric layer to expose the sidewalls of the trench above the hard mask or the conductive material; and forming a third dielectric layer over the hard mask or conductive material layer and the exposed sidewalls of the trench. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for manufacturing a semiconductor device, the method comprising:
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etching a trench into a doped semiconductor substrate including a drift zone and a drain region; forming a first dielectric layer over the substrate; providing positive charges over the first dielectric layer; depositing an etch stop material layer over the positive charges; depositing a silicon layer over the etch stop material layer; oxidizing a portion of the silicon layer; depositing a hard mask material in the trench; recess etching the hard mask material to expose portions of the oxidized silicon layer; etching the oxidized silicon layer and portions of the silicon layer to form a slope from the silicon layer on the sidewalls of the trench adjacent the hard mask; removing the hard mask; oxidizing the sloped silicon layer; depositing a conductive material layer over the oxidized sloped silicon layer; recess etching the conductive material layer to expose portions of the sidewalls of the trench to provide a tapered field plate; and forming a third dielectric layer over the conductive material layer and the exposed sidewalls of the trench. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification