METHOD OF FORMING TRENCH SEMICONDUCTOR DEVICE HAVING MULTIPLE TRENCH DEPTHS
First Claim
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1. A method of forming a semiconductor device comprising:
- providing a region of semiconductor material having a first conductivity type and a major surface;
forming a termination trench extending from a first portion of the major surface into the region of semiconductor material, wherein;
at least a portion of the termination trench extends to a first depth; and
the termination trench has a first width;
forming an active trench extending from a second portion of the major surface into the region of semiconductor material to a second depth, wherein;
the active trench has a second width less than the first width;
the first depth is greater than the second depth;
a portion of the region of semiconductor material is laterally interposed between the active trench and the termination trench in a cross-sectional view; and
the portion of the region of semiconductor material is devoid of trench structures whereby the active trench is a closest trench structure to the termination trench in the cross-sectional view;
forming a first conductive material having a first portion within the active trench and separated from the region of semiconductor material by a first dielectric region and a second portion within the termination trench separated from the region of semiconductor material by a second dielectric region; and
forming a second conductive material adjoining a third portion of the major surface, wherein the second conductive material is configured to provide a Schottky barrier.
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Abstract
A method of forming a semiconductor includes a providing a termination trench and an active trench within a semiconductor layer. The active trench is configured to be at a shallower depth than the termination trench to provide a trench depth difference. The selected trench depth difference in combination with one or more of the dopant concentration of the semiconductor layer, the thickness of the semiconductor layer, active trench width to termination trench width, and/or dopant profile of the semiconductor layer provide a semiconductor device having improved performance characteristics.
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Citations
20 Claims
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1. A method of forming a semiconductor device comprising:
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providing a region of semiconductor material having a first conductivity type and a major surface; forming a termination trench extending from a first portion of the major surface into the region of semiconductor material, wherein; at least a portion of the termination trench extends to a first depth; and the termination trench has a first width; forming an active trench extending from a second portion of the major surface into the region of semiconductor material to a second depth, wherein; the active trench has a second width less than the first width; the first depth is greater than the second depth; a portion of the region of semiconductor material is laterally interposed between the active trench and the termination trench in a cross-sectional view; and the portion of the region of semiconductor material is devoid of trench structures whereby the active trench is a closest trench structure to the termination trench in the cross-sectional view; forming a first conductive material having a first portion within the active trench and separated from the region of semiconductor material by a first dielectric region and a second portion within the termination trench separated from the region of semiconductor material by a second dielectric region; and forming a second conductive material adjoining a third portion of the major surface, wherein the second conductive material is configured to provide a Schottky barrier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of forming a semiconductor device comprising:
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providing a region of semiconductor material comprising a semiconductor layer adjoining a semiconductor substrate, the semiconductor layer defining a major surface, wherein the semiconductor layer has a first dopant concentration and the semiconductor substrate has a second dopant concentration greater than the first dopant concentration; in a single step; forming a termination trench extending from a first portion of the major surface into the region of semiconductor material, wherein the first trench extends to a first depth, and wherein the termination trench has a first width; and forming a plurality of active trenches each extending from a second portion of the major surface into the region of semiconductor material to a second depth, wherein each active trench has a second width less than the first width, and wherein the first depth is greater than the second depth to define a trench depth difference, and wherein one of the active trenches is disposed in the region of semiconductor material as a closest trench structure to the termination trench; forming a first conductive material within each active trench and separated from the region of semiconductor material by a dielectric region; and forming a second conductive material having a first portion adjoining a third portion of the major surface, wherein the first portion of the second conductive material is configured to provide a Schottky barrier. - View Dependent Claims (17)
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18. A method of forming a Schottky semiconductor device comprising:
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providing a region of semiconductor material comprising a semiconductor layer adjacent a semiconductor substrate, the semiconductor layer defining a major surface, wherein the semiconductor layer has a first dopant concentration and the semiconductor substrate has a second dopant concentration greater than the first dopant concentration; forming a termination trench extending from a first portion of the major surface into the region of semiconductor material, wherein; the termination trench extends to a first depth; and the termination trench has a first width; forming an active trench extending from a second portion of the major surface into the region of semiconductor material to a second depth, wherein; the active trench has a second width less than the first width; the first depth is greater than the second depth to provide a trench depth difference; a portion of the region of semiconductor material is laterally interposed between the active trench and the termination trench in a cross-sectional view; and the portion of the region of semiconductor material is devoid of trench structures so that the active trench is a closest trench structure to the termination trench in the cross-sectional view; forming a first conductive material within the second trench and separated from the region of semiconductor material by a dielectric region; and forming a second conductive material adjoining a third portion of the major surface, wherein the second conductive material is configured to provide a Schottky barrier. - View Dependent Claims (19, 20)
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Specification