Charged balanced devices with shielded gate trench
First Claim
1. A method for forming a semiconductor power device on a semiconductor substrate comprising:
- providing a semiconductor substrate;
opening a plurality of deep, trenches in the semiconductor substrate and growing an epitaxial layer that fills said deep trenches and covers a top surface of said semiconductor substrate with a top epitaxial layer, wherein the portions of the epitaxial layer in the epitaxial deep trench and said top epitaxial layer are simultaneously grown as a single layer and wherein the epitaxial layer is of an opposite conductivity type as the semiconductor substrate; and
forming a plurality of trench MOSFET cells in said top epitaxial layer by opening a plurality of trench gates and implanting a plurality of gate-shielding dopant regions below said gate trenches for shielding trench gates of said transistor cells during a voltage breakdown of said semiconductor power device with the top epitaxial layer acting as the body region and the semiconductor substrate acting as the drain region, wherein a super junction effect is achieved through charge balance between the portions of the epitaxial layer in the deep trenches and the portions of the semiconductor substrate lateral to the deep trenches.
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Accused Products
Abstract
This invention discloses a semiconductor power device disposed on a semiconductor substrate includes a plurality of deep trenches with an epitaxial layer filling said deep trenches and a simultaneously grown top epitaxial layer covering areas above a top surface of said deep trenches over the semiconductor substrate. A plurality of trench MOSFET cells disposed in said top epitaxial layer with the top epitaxial layer functioning as the body region and the semiconductor substrate acting as the drain region whereby a super-junction effect is achieved through charge balance between the epitaxial layer in the deep trenches and regions in the semiconductor substrate laterally adjacent to the deep trenches. Each of the trench MOSFET cells further includes a trench gate and a gate-shielding dopant region disposed below and substantially aligned with each of the trench gates for each of the trench MOSFET cells for shielding the trench gate during a voltage breakdown.
47 Citations
9 Claims
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1. A method for forming a semiconductor power device on a semiconductor substrate comprising:
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providing a semiconductor substrate; opening a plurality of deep, trenches in the semiconductor substrate and growing an epitaxial layer that fills said deep trenches and covers a top surface of said semiconductor substrate with a top epitaxial layer, wherein the portions of the epitaxial layer in the epitaxial deep trench and said top epitaxial layer are simultaneously grown as a single layer and wherein the epitaxial layer is of an opposite conductivity type as the semiconductor substrate; and forming a plurality of trench MOSFET cells in said top epitaxial layer by opening a plurality of trench gates and implanting a plurality of gate-shielding dopant regions below said gate trenches for shielding trench gates of said transistor cells during a voltage breakdown of said semiconductor power device with the top epitaxial layer acting as the body region and the semiconductor substrate acting as the drain region, wherein a super junction effect is achieved through charge balance between the portions of the epitaxial layer in the deep trenches and the portions of the semiconductor substrate lateral to the deep trenches. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification