Semiconductor memory device and semiconductor memory system
View Patent ↗A semiconductor memory device includes a plurality of memory cell arrays each including a plurality of memory cells arranged in a matrix pattern, and a plurality of cell plate lines each being shared by the memory cell arrays, each of the cell plate lines corresponding to each of rows of the memory cells and each of the cell plate lines being connected to the memory cells of a corresponding one of the rows. Each of the memory cell arrays includes a plurality of word lines each of which corresponds to each of the rows of the memory cells in the memory cell array. The number of the memory cells connected to each of the cell plate lines is larger than the number of the memory cells connected to one of the word lines corresponding to the each of the cell plate lines.
1. A semiconductor memory device, comprising:
a plurality of memory cell arrays each including a plurality of memory cells arranged in a matrix pattern; and
a plurality of cell plate lines each being shared by the memory cell arrays, each of the cell plate lines corresponding to each of rows of the memory cells and each of the cell plate lines being connected to the memory cells of a corresponding one of the rows, wherein
each of the memory cell arrays includes a plurality of word lines each of which corresponds to each of the rows of the memory cells in the memory cell array and each of the word lines is connected to the memory cells of a corresponding one of the rows; and
the number of the memory cells connected to each of the cell plate lines is larger than the number of the memory cells connected to one of the word lines corresponding to the each of the cell plate lines.
2. The semiconductor memory device of claim 1 , further comprising a plurality of first cell plate driving elements each driving a corresponding one of the cell plate lines based on a row decoder signal generated from a row address.
3. The semiconductor memory device of claim 2 , further comprising a plurality of second cell plate driving elements each driving a corresponding one of the cell plate lines based on a row decoder signal generated from a row address, each set of two or more of the second cell plate driving elements corresponding to each of the cell plate lines.
4. The semiconductor memory device of claim 3 , wherein one or more dummy memory cells are used as at least some of the second cell plate driving elements.
5. The semiconductor memory device of claim 3 ,
wherein each of the first cell plate driving elements includes
a NAND circuit receiving the row decoder signal, and
an inverter circuit receiving an output signal of the NAND circuit, and
wherein each of the second cell plate driving elements is a transfer gate.
6. The semiconductor memory device of claim 1 , further comprising a plurality of main word lines each of which corresponds to each of the rows of the memory cells of the memory cell arrays, the main word lines being activated based on a row address,
wherein each of the main word lines is connected, via a control element, to one of the word lines of the memory cell arrays that is connected to the memory cells of the row corresponding to the main word line.
7. The semiconductor memory device of claim 6 , further comprising a plurality of first cell plate driving elements each driving a corresponding one of the cell plate lines,
wherein each of the first cell plate driving elements is controlled by the main word line corresponding to the row of the memory cells connected to one of the cell plate lines that is driven by the each of the first cell plate driving elements.
8. The semiconductor memory device of claim 7 , further comprising a plurality of second cell plate driving elements each driving a corresponding one of the cell plate lines, each set of two or more of the second cell plate driving elements corresponding to each of the cell plate lines;
wherein each of the second cell plate driving elements is controlled by the main word line corresponding to the row of the memory cells connected to one of the cell plate lines that is driven by the each of the second cell plate driving elements.
9. The semiconductor memory device of claim 8 , wherein one or more dummy memory cells are used as at least some of the second cell plate driving elements.
10. The semiconductor memory device of claim 8 ,
wherein each of the first cell plate driving elements includes
a NAND circuit receiving a signal of the main word line corresponding to the row of the memory cells connected to one of the cell plate lines that is driven by the each of the first cell plate driving elements, and
an inverter circuit receiving an output signal of the NAND circuit, and
wherein each of the second cell plate driving elements is a transfer gate.
11. The semiconductor memory device of claim 1 , wherein each of the memory cells includes a transistor, and a ferroelectric capacitor connected to the transistor.
12. The semiconductor memory device of claim 11 , wherein
each of the memory cell arrays includes a plurality of bit line pairs each of which corresponds to each of columns of the memory cells of the memory cell array and each of the bit line pairs is connected to the memory cells of a corresponding one of the columns;
the semiconductor memory device further comprises a sense amplifier for amplifying a potential difference read out to each of the bit line pairs; and
when the sense amplifier starts the amplification, the transistor of the memory cell on which a read operation is being performed is in a non-conductive state.
13. A semiconductor memory system, comprising:
a semiconductor memory device; and
a memory controller for outputting a control signal for controlling the semiconductor memory device,
wherein the semiconductor memory device includes
a plurality of memory blocks, and
a column decoder for decoding a column address to generate a column selection signal specifying a column to be activated,
wherein each of the memory blocks includes
a plurality of memory cell arrays each including a plurality of memory cells arranged in a matrix pattern, and
a plurality of cell plate lines each being shared by the memory cell arrays, each of the cell plate lines corresponding to each of rows of the memory cells and each of the cell plate lines being connected to the memory cells of a corresponding one of the rows,
wherein each of the memory cell arrays includes a plurality of word lines each of which corresponds to each of the rows of the memory cells in the memory cell array and each of the word lines is connected to the memory cells of a corresponding one of the rows, and
the number of the memory cells connected to each of the cell plate lines is larger than the number of the memory cells connected to one of the word lines corresponding to the each of the cell plate lines, and
wherein the column decoder generates the column selection signal so that the memory block(s) of which number is determined based on the control signal are activated while one of the cell plate lines is active.
14. The semiconductor memory system of claim 13 , wherein the column decoder generates the column selection signal so that adjacent ones of the memory blocks are activated.