Superjunction structures for power devices and methods of manufacture
First Claim
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1. A method comprising:
- forming an N-type epitaxial layer over a substrate;
forming a P-type body region in the N-type epitaxial layer;
forming planar gate electrodes extending adjacent to but being insulated from the N-type epitaxial layer by a gate dielectric;
after forming the P-type body region and the gate electrodes, forming a plurality of deep trenches extending in the N-type epitaxial layer, each of the plurality of deep trenches extending through the P-type body region and having a bottom surface disposed within the N-type epitaxial layer; and
filling the plurality of deep trenches with P-type silicon to form a plurality of P-pillars, portions of the N-type epitaxial layer separating the plurality of P-pillars forming N-pillars such that the P-pillars and the N-pillars form directly-adjacent pillars of alternating conductivity type, the P-pillars and the N-pillars being of substantially a same height.
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Abstract
A power device includes a semiconductor region which in turn includes a plurality of alternately arranged pillars of first and second conductivity type. Each of the plurality of pillars of second conductivity type further includes a plurality of implant regions of the second conductivity type arranged on top of one another along the depth of pillars of second conductivity type, and a trench portion filled with semiconductor material of the second conductivity type directly above the plurality of implant regions of second conductivity type.
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Citations
19 Claims
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1. A method comprising:
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forming an N-type epitaxial layer over a substrate; forming a P-type body region in the N-type epitaxial layer; forming planar gate electrodes extending adjacent to but being insulated from the N-type epitaxial layer by a gate dielectric; after forming the P-type body region and the gate electrodes, forming a plurality of deep trenches extending in the N-type epitaxial layer, each of the plurality of deep trenches extending through the P-type body region and having a bottom surface disposed within the N-type epitaxial layer; and filling the plurality of deep trenches with P-type silicon to form a plurality of P-pillars, portions of the N-type epitaxial layer separating the plurality of P-pillars forming N-pillars such that the P-pillars and the N-pillars form directly-adjacent pillars of alternating conductivity type, the P-pillars and the N-pillars being of substantially a same height. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus, comprising:
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an epitaxial layer of a first conductivity type disposed over a substrate; a body region of a second conductivity type disposed in the epitaxial layer; a planar gate electrode extending adjacent to and insulated from the epitaxial layer by a gate dielectric; and a plurality of trenches extending in the epitaxial layer, each trench from the plurality of trenches including a silicon of the second conductivity type to form a plurality of pillars of the second conductivity type, portions of the epitaxial layer separating the plurality of pillars of the second conductivity type forming directly-adjacent pillars of the first conductivity type such that the pillars of the first conductivity type alternate with the pillars of the second conductivity type, each of the plurality of trenches extending through the body region and terminating within the epitaxial layer, such that a discontinuity is defined in the body region, the pillars of the first conductivity type and the pillars of the second conductivity type being of substantially a same height. - View Dependent Claims (12, 13, 14)
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15. An apparatus, comprising:
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an epitaxial layer of a first conductivity type disposed over a substrate; a body region of a second conductivity type disposed in the epitaxial layer; a planar gate electrode extending adjacent to and insulated from the epitaxial layer by a gate dielectric; a first trench disposed in the epitaxial layer and including silicon of the second conductivity type disposed therein; and a second trench disposed in the epitaxial layer and including a silicon of the second conductivity type disposed therein, the first trench and the second trench extending through the body region such that the body region is divided into a first portion, a second portion and a third portion, the first trench, the second trench and the epitaxial layer being of substantially a same height. - View Dependent Claims (16, 17, 18, 19)
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Specification