Circuit and method for an open bit line memory cell with a vertical transistor and trench plate trench capacitor
First Claim
1. A method of fabricating an array of memory cells, comprising:
- providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate;
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator; and
wherein forming the access transistors includes forming a first layer of material of a first conductivity type outwardly from the substrate, forming a second layer of material of a second conductivity type outwardly from the first layer, and forming a third layer of material of the first conductivity type outwardly from the second layer.
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Accused Products
Abstract
A memory cell. The memory cell includes an access transistor. The access transistor is formed in a pillar of single crystal semiconductor material. The transistor has first and second source/drain regions and a body region that are vertically aligned. The memory cell also includes a body contact that is coupled to the body region. A gate of the transistor is disposed on a side of the pillar that is opposite from the body contact. A trench capacitor is also included. The trench capacitor includes a first plate that is formed integral with the first source/drain region of the access transistor and a second plate that is disposed adjacent to the first plate and separated from the first plate by a gate oxide. An insulator layer that separates the access transistor and the trench capacitor from an underlying layer of semiconductor material.
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Citations
24 Claims
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1. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate;
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator; and
wherein forming the access transistors includes forming a first layer of material of a first conductivity type outwardly from the substrate, forming a second layer of material of a second conductivity type outwardly from the first layer, and forming a third layer of material of the first conductivity type outwardly from the second layer. - View Dependent Claims (2)
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3. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate;
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator; and
wherein forming the plurality of access transistors includes forming column isolation trenches between adjacent columns of the access transistors and also includes forming row isolation trenches between adjacent rows of the access transistors. - View Dependent Claims (4)
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5. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate;
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator; and
wherein forming the plurality of access transistors includes forming column and row isolation trenches between adjacent columns and rows of the access transistors, respectively, and wherein forming the trench capacitor for each access transistor includes forming a conductive grid disposed in the column and row isolation trenches. - View Dependent Claims (6, 7)
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8. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate, wherein forming the plurality of access transistors includes;
forming a first layer of material of a first conductivity type on the substrate, forming a second layer of material of a second conductivity type on the first layer, forming a third layer of material of the first conductivity type on the second layer, forming column isolation trenches between adjacent columns of the access transistors, and forming row isolation trenches between adjacent rows of the access transistors; and
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate, each pillar having a first pair of opposite sides defined by adjacent column isolation trenches and a second pair of opposite sides defined by adjacent row isolation trenches; and
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator, the second plate being formed by a conductive grid in the column and row isolation trenches. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate, each pillar having a first pair of opposite sides defined by adjacent column isolation trenches and a second pair of opposite sides defined by adjacent row isolation trenches;
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator; and
forming a plurality of body address lines in the row isolation trenches, wherein each body address line interconnects the body regions of access transistors that form a row of the array. - View Dependent Claims (23)
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24. A method of fabricating an array of memory cells, comprising:
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providing a substrate;
forming a plurality of access transistors, each access transistor formed in a pillar of semiconductor material extending outwardly from the substrate and including a first source/drain region, a body region, and a second source/drain region formed vertically on the substrate, wherein forming the access transistors includes forming a first layer of material of a first conductivity type on the substrate, forming a second layer of material of a second conductivity type on the first layer, forming a third layer of material of the first conductivity type on the second layer, forming column isolation trenches between adjacent columns of the access transistors, and forming row isolation trenches between adjacent rows of the access transistors;
forming a trench capacitor for each access transistor, each trench capacitor including a first plate formed integral with the first source/drain region of the respective access transistor and a second plate disposed adjacent to the first plate and separated therefrom by an insulator;
forming a plurality of word lines disposed in the row isolation trenches, wherein each word line interconnects gates of a plurality of access transistors that form a row of the array;
forming a plurality of body address lines in the row isolation trenches, wherein each body address line interconnects the body regions of access transistors that form a row of the array; and
forming a plurality of bit lines interconnecting the second source/drain regions of a plurality of access transistors that form a column of the array.
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Specification