SEMICONDUCTOR MEMORY DEVICE
First Claim
1. A semiconductor memory device, comprising:
- a memory cell array formed of a number of memory cells aligned in a matrix shape in a row direction and a column direction, each memory cell comprising a memory element and a cell transistor, wherein the memory element has two input/output terminals so that information is stored using a difference in electrical properties between the two terminals and the stored information is written by applying a writing voltage across the two terminals, the cell transistor has two input/output terminals and one control terminal, and a first end of the input/output terminal of the memory element and a first end of the input/output terminal of the cell transistor are connected;
word lines extending in the row direction for connecting control terminals of the cell transistors in the memory cells aligned in same rows to each other;
first bit lines extending in the column direction for connecting second ends of the input/output terminals of the cell transistors in the memory cells aligned in same columns to each other, the second end being not connected to the memory elements;
second bit lines extending in the row or column direction for connecting second ends of the input/output terminals of the memory elements in the memory cells to each other, the second ends being not connected to the cell transistors;
a word line voltage applying circuit for applying a voltage to a word line connected to the memory cell selected to be written;
a first voltage applying circuit for applying the writing voltage to the first bit line connected to the selected memory cell; and
a second voltage applying circuit for applying a pre-charge voltage to both the first bit line and the second bit line connected to the selected memory cell before application of the writing voltage.
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Accused Products
Abstract
There is provided a semiconductor memory device capable of suppressing writing disturbances without increasing the cell array area. A semiconductor memory device has a memory cell array where a number of memory cells having a two-terminal type memory element and a transistor for selection connected in series are aligned in a matrix shape, a first voltage applying circuit for applying a writing voltage pulse to a first bit line, and a second voltage applying circuit for applying a pre-charge voltage to a first and second bit line, such that at the time of the writing of a memory cell, the first voltage applying circuit pre-charges the two ends of the memory cell to the same voltage in advance, and after that, the second voltage applying circuit applies a writing voltage pulse via the first bit line directly connected to the transistor for selection.
23 Citations
15 Claims
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1. A semiconductor memory device, comprising:
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a memory cell array formed of a number of memory cells aligned in a matrix shape in a row direction and a column direction, each memory cell comprising a memory element and a cell transistor, wherein the memory element has two input/output terminals so that information is stored using a difference in electrical properties between the two terminals and the stored information is written by applying a writing voltage across the two terminals, the cell transistor has two input/output terminals and one control terminal, and a first end of the input/output terminal of the memory element and a first end of the input/output terminal of the cell transistor are connected; word lines extending in the row direction for connecting control terminals of the cell transistors in the memory cells aligned in same rows to each other; first bit lines extending in the column direction for connecting second ends of the input/output terminals of the cell transistors in the memory cells aligned in same columns to each other, the second end being not connected to the memory elements; second bit lines extending in the row or column direction for connecting second ends of the input/output terminals of the memory elements in the memory cells to each other, the second ends being not connected to the cell transistors; a word line voltage applying circuit for applying a voltage to a word line connected to the memory cell selected to be written; a first voltage applying circuit for applying the writing voltage to the first bit line connected to the selected memory cell; and a second voltage applying circuit for applying a pre-charge voltage to both the first bit line and the second bit line connected to the selected memory cell before application of the writing voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification