Rectifier diode
First Claim
1. A pseudo-Schottky diode comprising:
- an n-channel trench MOSFET that includes;
a drain with a cathode metal;
an anode metal; and
located between the cathode metal and the anode metal, the following elements;
a highly n+-doped silicon substrate;
an n-doped epilayer having trenches extending into the n-doped epilayer from above; and
p-doped body regions provided above the n-doped epilayer and between the trenches;
wherein;
highly n+-doped regions forming a source of the MOSFET and highly p+-doped regions are provided on the upper surface of the p-doped body regions;
dielectric layers are provided on the side walls of the trenches;
with respect to at least one of the trenches;
a first p-doped layer, which is a polysilicon layer, forms a gate of the MOSFET, fills a first portion of the respective trench, and is electrically connected to the highly n+-doped regions and the highly p+-doped regions via a layer of the anode metal that extends from over the first p-doped layer to over the highly n+-doped regions and the highly p+-doped regions;
a second p-doped layer is;
in contact with an entirety of a bottom face of the first p-doped layer;
is at a bottom-most region of the respective trench;
extends to below a lowest point of that of the dielectric layers which is included in the respective trench; and
is in contact with at least one of the n-doped epilayer and the highly n+-doped silicon substrate; and
a breakdown voltage of a junction between the second p-doped layer and the at least one of the n-doped epilayer and the highly n+-doped silicon substrate (a) is lower than a breakdown voltage between the first p-doped layer and the n-doped epilayer and (b) thereby forms the breakdown voltage of the pseudo-Schottky diode; and
the gate, the body regions, and the source are monolithically and electrically connected to one another.
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Accused Products
Abstract
A pseudo-Schottky diode has an n-channel trench MOSFET which includes: a cathode, an anode, and located between the cathode and the anode, the following elements: a highly n+-doped silicon substrate; an n-doped epilayer having a trench extending into the n-doped epilayer from above; p-doped body regions provided above the n-doped epilayer and between the trenches. Highly n+-doped regions and highly p+-doped regions are provided on the upper surface of the p-doped body regions. Dielectric layers are provided on the side walls of the trench. The trench is filled with a first p-doped polysilicon layer, and the bottom of the trench is formed by a second p-doped layer which is in contact with the first p-doped polysilicon layer, and the second p-doped layer determines the breakdown voltage of the pseudo-Schottky diode.
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Citations
21 Claims
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1. A pseudo-Schottky diode comprising:
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an n-channel trench MOSFET that includes; a drain with a cathode metal; an anode metal; and located between the cathode metal and the anode metal, the following elements; a highly n+-doped silicon substrate; an n-doped epilayer having trenches extending into the n-doped epilayer from above; and p-doped body regions provided above the n-doped epilayer and between the trenches; wherein; highly n+-doped regions forming a source of the MOSFET and highly p+-doped regions are provided on the upper surface of the p-doped body regions; dielectric layers are provided on the side walls of the trenches; with respect to at least one of the trenches; a first p-doped layer, which is a polysilicon layer, forms a gate of the MOSFET, fills a first portion of the respective trench, and is electrically connected to the highly n+-doped regions and the highly p+-doped regions via a layer of the anode metal that extends from over the first p-doped layer to over the highly n+-doped regions and the highly p+-doped regions; a second p-doped layer is; in contact with an entirety of a bottom face of the first p-doped layer; is at a bottom-most region of the respective trench; extends to below a lowest point of that of the dielectric layers which is included in the respective trench; and is in contact with at least one of the n-doped epilayer and the highly n+-doped silicon substrate; and a breakdown voltage of a junction between the second p-doped layer and the at least one of the n-doped epilayer and the highly n+-doped silicon substrate (a) is lower than a breakdown voltage between the first p-doped layer and the n-doped epilayer and (b) thereby forms the breakdown voltage of the pseudo-Schottky diode; and the gate, the body regions, and the source are monolithically and electrically connected to one another. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A circuit comprising:
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a load; and a pseudo-Schottky diode that includes an n-channel trench MOSFET, the n-channel trench MOSFET including; a drain, which is a cathode; an anode; and located between the cathode and the anode, the following elements; a highly n+-doped silicon substrate; an n-doped epilayer having trenches extending into the n-doped epilayer from above; and p-doped body regions provided above the n-doped epilayer and between the trenches; wherein; highly n+-doped regions forming a source of the MOSFET and highly p+-doped regions are provided on the upper surface of the p-doped body regions; dielectric layers are provided on the side walls of the trenches; with respect to at least one of the trenches; a first p-doped layer, which is a polysilicon layer, forms a gate and fills a first portion of the respective trench and is electrically connected to the highly n+-doped regions and the highly p+-doped regions via a layer of the anode that extends from over the first p-doped layer to over the highly n+-doped regions and the highly p+-doped regions; a second p-doped layer that; is in contact with an entirety of a bottom face of the first p-doped layer; is at a bottom-most region of the respective trench; extends to below a lowest point of that of the dielectric layers which is included in the respective trench; and is in contact with at least one of the n-doped epilayer and the highly n+-doped silicon substrate; and a breakdown voltage of a junction between the second p-doped layer and the at least one of the n-doped epilayer and the highly n+-doped silicon substrate (a) is lower than a breakdown voltage between the first p-doped layer and the n-doped epilayer and (b) thereby forms the breakdown voltage of the pseudo-Schottky diode; and the gate, the body regions, and the source are monolithically and electrically connected to one another. - View Dependent Claims (18, 19, 20, 21)
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Specification