3D channel architecture for semiconductor devices
First Claim
1. A semiconductor device, comprising:
- a semiconductor substrate containing a source region in an upper portion of the substrate;
a dual trench structure in an upper portion of the substrate, wherein the dual trench structure contains;
a plurality of discrete lower trenches separated by a mesa between adjacent lower trenches, the lower trenches having sidewalls extending in both an x- and a y-direction; and
an upper trench overlying the lower trenches, the upper trench having sidewalls extending in the y direction that are longer than the sidewalls extending in the x direction;
an oxide layer located on the bottom, sidewall of the lower trenches, and sidewall of the upper trench;
a first conductive or semi-conductive layer located on the oxide layer in the lower trenches; and
a second conductive or semi-conductive layer located on the first conductive or semi-conductive layer and the mesa.
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Accused Products
Abstract
Semiconductor devices and methods for making such devices that contain a 3D channel architecture are described. The 3D channel architecture is formed using a dual trench structure containing with a plurality of lower trenches extending in an x and y directional channels and separated by a mesa and an upper trench extending in a y direction and located in an upper portion of the substrate proximate a source region. Thus, smaller pillar trenches are formed within the main line-shaped trench. Such an architecture generates additional channel regions which are aligned substantially perpendicular to the conventional line-shaped channels. The channel regions, both conventional and perpendicular, are electrically connected by their corner and top regions to produce higher current flow in all three dimensions. With such a configuration, higher channel density, a stronger inversion layer, and a more uniform threshold distribution can be obtained for the semiconductor device. Other embodiments are described.
23 Citations
24 Claims
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1. A semiconductor device, comprising:
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a semiconductor substrate containing a source region in an upper portion of the substrate; a dual trench structure in an upper portion of the substrate, wherein the dual trench structure contains; a plurality of discrete lower trenches separated by a mesa between adjacent lower trenches, the lower trenches having sidewalls extending in both an x- and a y-direction; and an upper trench overlying the lower trenches, the upper trench having sidewalls extending in the y direction that are longer than the sidewalls extending in the x direction; an oxide layer located on the bottom, sidewall of the lower trenches, and sidewall of the upper trench; a first conductive or semi-conductive layer located on the oxide layer in the lower trenches; and a second conductive or semi-conductive layer located on the first conductive or semi-conductive layer and the mesa. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A trench MOSFET device containing a three dimensional channel architecture, comprising:
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a silicon substrate with an epitaxial layer in an upper portion thereof, the epitaxial layer containing a source region in an upper portion thereof; a dual trench structure in an upper portion of the substrate, wherein the dual trench structure contains; a plurality of discrete lower trenches separated by a mesa between adjacent lower trenches, the lower trenches having sidewalls extending both in an x- and a y-direction; and an upper trench overlying the lower trenches, the upper trench having sidewalls extending in the y direction that are longer than the sidewalls extending in the x direction; a gate oxide layer located on the bottom, sidewall of the lower trenches, and sidewall of the upper trench; a polysilicon gate located on the gate oxide layer in the lower trenches; a conductive layer located on the polysilicon gate and the mesa and in the upper trench; and an insulating layer located on the conductive layer in the upper trench between the source region. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A trench MOSFET device containing a three dimensional channel architecture, comprising:
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a silicon substrate with an epitaxial layer in an upper portion thereof, the epitaxial region layer containing a source region in an upper portion thereof; a dual trench structure in an upper portion of the substrate, wherein the dual trench structure contains; a plurality of discrete lower trenches separated by a mesa between adjacent lower trenches, the lower trenches having sidewalls extending in both an x- and a y-direction; and an upper trench overlying the lower trenches, the upper trench having sidewalls extending in the y direction that are longer than the sidewalls extending in the x direction; thereby forming channels extending in the x and y directions and in a z direction and making a three dimensional channel structure so that current flows through the dual trench structure in three dimensions; a gate oxide layer located on the bottom, sidewall of the lower trenches, and sidewall of the upper trench; a polysilicon gate located on the gate oxide layer in the lower trenches; a conductive layer located on the polysilicon gate and the mesa and in the upper trench; and an insulating layer located on the conductive layer in the upper trench between the source region.
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23. A semiconductor device, comprising:
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a semiconductor substrate containing a source region in an upper portion of the substrate; a dual trench structure in an upper portion of the substrate, wherein the dual trench structure contains with a plurality of lower trenches extending in both x- and y-directional channels and separated by a mesa and an upper trench extending in a y direction and located in an upper portion of the substrate proximate the source region;
wherein the width of the lower trenches in the x direction is more than the length of the mesa separating adjacent lower trenches,an oxide layer located on the bottom, sidewall of the lower trenches, and sidewall of the upper trench; a first portion of a conductive or semi-conductive layer located on the oxide layer in the lower trenches; and a second portion of a conductive or semi-conductive layer located on the first conductive layer and the mesa. - View Dependent Claims (24)
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Specification