Simplified nonvolatile memory cell string and nand flash memory array using the same
AssigneeSeoul National University R&Db Foundation
InventorJong-Ho LEE
Life of this patent
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Abstract
The present invention provides a nonvolatile memory cell string and a NAND flash memory array using the same. According to the present invention, a wall type semiconductor separated into twin fins can increase the degree of integration and basically prevent the interferences between adjacent cells. And gate electrodes formed to cover depletion regions between the channel and source regions or between the channel and drain regions enable GIDL to be used for a memory operation without GSL and CSL which are necessarily needed in the conventional NAND flash memory array and can significantly increase the degree of integration.
Claims20
A nonvolatile memory cell string comprising:
- two or more cell devices formed in series on a wall type semiconductor protruded from a semiconductor substrate with a predetermined length along one direction to form the cell string,
- wherein one end of the cell string is electrically connected to outside through a string selection transistor formed on one end of the wall type semiconductor, and
- wherein the other end of the cell string is floated and not electrically connected to outside.
A NAND flash memory array comprising:
- a plurality of cell strings formed to have a predetermined length along one direction on a semiconductor substrate;
- a plurality of word lines formed to intersect each of the cell strings;
- a plurality of bit lines electrically connected to one end of each of the cell strings;
- and
- one or more string selection lines to select each of the cell strings,
- wherein each of the cell strings is formed on a wall type semiconductor protruded from the semiconductor substrate,
- wherein the string selection line is formed to intersect the wall type semiconductor at least by one side of the plurality of word lines,
- wherein each of the bit lines is electrically connected to one end of each of the cell strings exposed to one side of the string selection line, and
- wherein the other end of each of the cell strings is floated and not electrically connected to outside.
Dependencies are inferred from the claim text.