Semiconductor device that uses a transistor for field shield
First Claim
1. A semiconductor device comprising:
- a semiconductor substrate including first, second and third portions;
the first and second portions being partitioned by a cell gate trench having a bottom surface, a first side surface located on the first portion side, and a second side surface located on the second portion side,the first and third portions being partitioned by a first field-shield gate trench exposing a third side surface located on the first portion side and a fourth side surface located on the third portion side, anda distance between the third and fourth surfaces being narrower than a distance between the first and second surfaces,a first upper diffusion layer that is provided on an upper part of the first portion of the semiconductor substrate;
a second upper diffusion layer that is provided on an upper part of the second portion of the semiconductor substrate;
a third upper diffusion layer that is provided on an upper part of the third portion of the semiconductor substrate;
a lower diffusion layer that is provided in the bottom surface of the cell gate trench;
a first and a second storage element that are electrically connected to the first and second upper diffusion layers, respectively;
a bit line that is electrically connected to the lower diffusion layer;
a first and a second cell gate electrode that cover the first and second side surfaces, respectively, via a gate insulating film; and
a first field-shield gate electrode that is embedded in the first field-shield gate trench via a gate insulating film.
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Accused Products
Abstract
A semiconductor device includes: a cell gate trench with a bottom face and first/second side faces; a field-shield gate trench narrower than the cell gate trench; a first upper diffusion layer between the cell gate trench and the field-shield gate trench; a second upper diffusion layer on the opposite side of the cell gate trench from the first upper diffusion layer; a third upper diffusion layer on the opposite side of the field-shield gate trench from the first upper diffusion layer; a lower diffusion layer on the bottom face of the cell gate trench; first and second storage elements electrically connected to the first and second upper diffusion layers, respectively; a bit line electrically connected to the lower diffusion layer; a word line covering first and second side faces via a gate insulating film; and a field-shield gate electrode in the field-shield gate trench via a gate insulating film.
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Citations
13 Claims
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1. A semiconductor device comprising:
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a semiconductor substrate including first, second and third portions; the first and second portions being partitioned by a cell gate trench having a bottom surface, a first side surface located on the first portion side, and a second side surface located on the second portion side, the first and third portions being partitioned by a first field-shield gate trench exposing a third side surface located on the first portion side and a fourth side surface located on the third portion side, and a distance between the third and fourth surfaces being narrower than a distance between the first and second surfaces, a first upper diffusion layer that is provided on an upper part of the first portion of the semiconductor substrate; a second upper diffusion layer that is provided on an upper part of the second portion of the semiconductor substrate; a third upper diffusion layer that is provided on an upper part of the third portion of the semiconductor substrate; a lower diffusion layer that is provided in the bottom surface of the cell gate trench; a first and a second storage element that are electrically connected to the first and second upper diffusion layers, respectively; a bit line that is electrically connected to the lower diffusion layer; a first and a second cell gate electrode that cover the first and second side surfaces, respectively, via a gate insulating film; and a first field-shield gate electrode that is embedded in the first field-shield gate trench via a gate insulating film. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A semiconductor device comprising:
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a semiconductor substrate having a plurality of cell gate trenches and a plurality of field-shield gate trenches that extend to a first direction in parallel, the cell gate trenches and the field-shield gate trenches are disposed so as to alternately appear in a second direction, each of the cell gate trenches exposing a bottom surface and first and second side surfaces of the semiconductor substrate, and each of the cell gate trenches is wider in the second direction than each of the field-shield gate trenches; a plurality of upper diffusion layers, each of which is provided on an upper part of the semiconductor substrate provided between an associated one of the cell gate trenches and an associated one of the field-shield gate trenches; a plurality of lower diffusion layers, each of which is provided in an associated one of the bottom surfaces; a plurality of storage elements, each of which is electrically connected to an associated one of the upper diffusion layers; a plurality of bit lines extending to the second direction, each of which is electrically connected to an associated one of the lower diffusion layers; a plurality of first cell gate electrodes, each of which covers the first side surface exposed on an associated one of the cell gate trenches via a gate insulating film; a plurality of second cell gate electrodes, each of which covers the second side surface exposed on an associated one of the cell gate trenches via a gate insulating film; and a plurality of field-shield gate electrodes, each of which is embedded in an associated one of the field-shield gate trenches via a gate insulating film. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification