Semiconductor memory device capable of increasing writing speed
A memory cell array has a structure in which a plurality of memory cells connected with word lines and bit lines and connected in series are arranged in a matrix form. A selection transistor selects the word lines. A control circuit controls potentials of the word lines and the bit lines in accordance with input data, and controls write, read and erase operations of data with respect to the memory cell. The selection transistor is formed on a well, and a first negative voltage is supplied to a well, a first voltage (the first voltage≧the first negative voltage) is supplied to a selected word line and a second voltage is supplied to a non-selected word line in the read operation.
1. A semiconductor memory device comprising:
a memory cell array having a plurality of memory cells which are arranged in a matrix form and connected in series, the plurality of memory cells being connected with word lines and bit lines;
a selection transistor which selects the word lines; and
a control circuit which controls potentials of the word lines and the bit lines in accordance with input data, the control circuit controlling write, read and erase operations of data with respect to the memory cells,
wherein the selection transistor is formed on a well, and a first negative voltage is supplied to the well, a first voltage (the first voltage≧the first negative voltage) is supplied to a selected word line and a second voltage is supplied to a non-selected word line in the read operation.
2. The device according to claim 1 , wherein the memory cell array has at least one block including at least one of the word lines,
the selection transistor is formed on the well arranged in each block, and the first negative voltage is supplied to the well corresponding to a selected block, and
one of the first negative voltage and a third voltage (the third voltage≧the first negative voltage) is supplied to the well corresponding to a non-selected block.
3. The device according to claim 2 , wherein, when a potential read from the memory cell is not negative, a fourth voltage (the first voltage≧the fourth voltage) is supplied to the well corresponding to the selected block.
4. The device according to claim 2 , wherein the selection transistor is formed on the well arranged in accordance with at least one of the blocks, and the first negative voltage is supplied to the well.
5. The device according to claim 1 , wherein at least one of a plurality of negative threshold voltages and a plurality of positive threshold voltages is set with respect to the memory cell.
6. The device according to claim 1 , wherein the control circuit has a negative voltage generator circuit which generates the first negative voltage.
7. The device according to claim 2 , wherein the selection transistor is included in a row decoder selecting the word line.
8. A semiconductor memory device comprising:
a memory cell array having a plurality of memory cells which are arranged in a matrix form and connected in series, the plurality of memory cells being connected with word lines and bit lines;
a selection transistor which selects the word lines; and
a control circuit which controls potentials of the word lines and the bit lines in accordance with input data, the control circuit controlling write, read and erase operations of data with respect to the memory cells,
wherein the selection transistor is formed on a well, and a first negative voltage is supplied to the well and a first voltage (the first voltage≧the first negative voltage) is supplied to a predetermined non-selected word line in the write operation.
9. The device according to claim 8 , wherein the memory cell array has at least one block including at least one of the word lines,
the selection transistor is formed on the well arranged in accordance with each block, and the first negative voltage is supplied to the well corresponding to a selected block, and
one of the first negative voltage and a second voltage (the second voltage≧the first negative voltage) is supplied to the well corresponding to a non-selected block.
10. The device according to claim 9 , wherein the selection transistor is formed on the well arranged in accordance with at least one of the blocks, and the first negative voltage is supplied to the well.
11. The device according to claim 8 , wherein one of a plurality of negative threshold voltages and a plurality of positive threshold voltages is set with respect to the memory cell.
12. The device according to claim 8 , wherein the first negative voltage is supplied to a gate electrode of a memory cell which is positioned on at least a source line side apart from a writing target memory cell.
13. The device according to claim 8 , wherein the control circuit has a negative voltage generator circuit which generates the first negative voltage.
14. The device according to claim 10 , wherein the selection transistor is included in a row decoder selecting the word line.
15. A semiconductor memory device comprising:
a memory cell array having a plurality of memory cells arranged in a matrix form, the plurality of memory cells being connected with word lines and bit lines;
a selection transistor which selects the word lines; and
a control circuit which controls potentials of the word lines and the bit lines in accordance with input data, the control circuit controlling write, read and erase operations of data with respect to the memory cells,
wherein the selection transistor is formed on a well, and a first negative voltage is supplied to the well and a first voltage (the first voltage≧the first negative voltage) is supplied to a selected word line in an erase verify read operation.
16. The device according to claim 15 , wherein the memory cell array has at least one block including at least one of the word lines,
the selection transistor is formed on a well arranged in accordance with each block, and the first negative voltage is supplied to the well corresponding to a selected block, and
one of the first negative voltage and a second voltage (the second voltage≧the first negative voltage) is supplied to the well corresponding to a non-selected block.
17. The device according to claim 16 , wherein the selection transistor is formed on the well arranged in accordance with at least one of the blocks, and the first negative voltage is supplied to the well.
18. The device according to claim 15 , wherein at least one of a plurality of negative threshold voltages and a plurality of positive threshold voltages is set with respect to the memory cell.
19. The device according to claim 15 , wherein the control circuit has a negative voltage generator circuit which generates the first negative voltage.
20. The device according to claim 17 , wherein the selection transistor is included in a row decoder selecting the word line.