Integrated circuit memory devices having vertically arranged strings of memory cells therein and methods of operating same
First Claim
1. A three-dimensional nonvolatile memory device, comprising:
- a first NAND-type string of EEPROM cells having a first plurality of string selection transistors therein electrically connected in series, said first plurality of string selection transistors comprising a first plurality of depletion-mode transistors and a first enhancement-mode transistor;
a second NAND-type string of EEPROM cells having a second plurality of string selection transistors therein electrically connected in series, said second plurality of string selection transistors comprising a second plurality of depletion-mode transistors and a second enhancement-mode transistor, said first enhancement-mode transistor stacked vertically relative to one of the second plurality of depletion-mode transistors and said second enhancement-mode transistor stacked vertically relative to one of the first plurality of depletion-mode transistors;
a first string selection line electrically connected to a gate electrode of the first enhancement-mode transistor and a gate electrode of the one of the second plurality of depletion-mode transistors; and
a second string selection line electrically connected to a gate electrode of the second enhancement-mode transistor and a gate electrode of the one of the first plurality of depletion-mode transistors;
wherein each of the first plurality of string selection transistors in said first NAND-type string of EEPROM cells is electrically coupled to a corresponding one of a plurality of string selection lines;
wherein each of the second plurality of string selection transistors in said second NAND-type string of EEPROM cells is electrically coupled to a corresponding one of the plurality of string selection lines;
wherein each of the first plurality of string selection transistors in said first NAND-type string of EEPROM cells is electrically coupled to only one of the plurality of string selection lines; and
wherein each of the second plurality of string selection transistors in said second NAND-type string of EEPROM cells is electrically coupled to only one of the plurality of string selection lines.
1 Assignment
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Accused Products
Abstract
Nonvolatile memory devices include a first NAND-type string of EEPROM cells having a first plurality of string selection transistors therein electrically connected in series within the string. This first plurality of string selection transistors includes a first plurality of depletion-mode transistors and a first enhancement-mode transistor. A second NAND-type string of EEPROM cells is also provided with a second plurality of string selection transistors therein that are electrically connected in series. The second plurality of string selection transistors includes a second plurality of depletion-mode transistors and a second enhancement-mode transistor. According to these embodiments of the invention, the first enhancement-mode transistor is stacked vertically relative to one of the second plurality of depletion-mode transistors and the second enhancement-mode transistor is stacked vertically relative to one of the first plurality of depletion-mode transistors. A first string selection plug is configured to electrically connect a gate electrode of the first enhancement-mode transistor to a gate electrode of one of the second plurality of depletion-mode transistors. Similarly, a second string selection plug is configured to electrically connect a gate electrode of the second enhancement-mode transistor to a gate electrode of one of the first plurality of depletion-mode transistors.
27 Citations
15 Claims
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1. A three-dimensional nonvolatile memory device, comprising:
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a first NAND-type string of EEPROM cells having a first plurality of string selection transistors therein electrically connected in series, said first plurality of string selection transistors comprising a first plurality of depletion-mode transistors and a first enhancement-mode transistor; a second NAND-type string of EEPROM cells having a second plurality of string selection transistors therein electrically connected in series, said second plurality of string selection transistors comprising a second plurality of depletion-mode transistors and a second enhancement-mode transistor, said first enhancement-mode transistor stacked vertically relative to one of the second plurality of depletion-mode transistors and said second enhancement-mode transistor stacked vertically relative to one of the first plurality of depletion-mode transistors; a first string selection line electrically connected to a gate electrode of the first enhancement-mode transistor and a gate electrode of the one of the second plurality of depletion-mode transistors; and a second string selection line electrically connected to a gate electrode of the second enhancement-mode transistor and a gate electrode of the one of the first plurality of depletion-mode transistors; wherein each of the first plurality of string selection transistors in said first NAND-type string of EEPROM cells is electrically coupled to a corresponding one of a plurality of string selection lines; wherein each of the second plurality of string selection transistors in said second NAND-type string of EEPROM cells is electrically coupled to a corresponding one of the plurality of string selection lines; wherein each of the first plurality of string selection transistors in said first NAND-type string of EEPROM cells is electrically coupled to only one of the plurality of string selection lines; and
wherein each of the second plurality of string selection transistors in said second NAND-type string of EEPROM cells is electrically coupled to only one of the plurality of string selection lines. - View Dependent Claims (2)
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3. A three-dimensional semiconductor device comprising:
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a first interconnection structure; a second interconnection structure; and a plurality of cell strings connecting the first and second interconnection structures in parallel, wherein each of the cell strings includes; a plurality of memory cell transistors connected in series; and a plurality of first selection transistors connecting in series the first interconnection structure and a memory cell transistor adjacent thereto; first selection lines connecting gate electrodes of the first selection transistors wherein one of the first selection transistors in one cell string is an enhancement mode transistor and the rest of the first selection transistors are depletion mode transistors; and wherein the number of the first selection transistors connected to one of the first selection lines is one in each of the cell strings. - View Dependent Claims (4, 5, 6, 7)
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8. A three-dimensional semiconductor device comprising:
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a bit line plug and a common source line plug spaced apart from each other on a substrate; a plurality of semiconductor patterns stacked sequentially on the substrate and connecting the bit line plug and the common source line plug in parallel; and a plurality of string selection transistors disposed on the semiconductor patterns, respectively, wherein the string selection transistors disposed on each of the semiconductor patterns include at least one enhancement mode transistor and at least one depletion mode transistor. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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Specification