Nonvolatile semiconductor memory device with scalable two transistor memory cells
View Patent ↗A nonvolatile memory device includes a bit line, a pair of data lines and a plurality of scalable two transistor memory (STTM) cells. The memory cells are arranged between a pair of datalines so as to share the bit line. The memory device further includes a data line selection circuit and a sense amplification circuit. The data line selection circuit selects one of a pair of data lines, and the sense amplification circuit senses and amplifies a voltage difference between the bit line and the selected data line. Operation speed is increased, while improving device cell array structure.
1. A nonvolatile memory device, comprising:
a common bit line;
first and second data lines;
a first group of scalable two transistor memory cells, each memory cell including a write transistor and a read transistor, the memory cells being connected in parallel with each other between the common bit line and the first data line; and
a second group of scalable two transistor memory cells, each memory cell including a write transistor and a read transistor, the second-group memory cells being connected in parallel with each other, and all of the memory cells of the second group being between the common bit line and the second data line.
2. The nonvolatile memory device of claim 1 , wherein a first group of control lines respectively are connected to the scalable two transistor memory cells of the first group, and a second group of control lines respectively are connected to the scalable two transistor memory cells of the second group, wherein the control lines of the first and second groups are alternately arranged.
3. The nonvolatile memory device of claim 1 , further comprising:
a selection circuit to select one of the first and the second data lines in response to control signals; and
a sense amplification circuit to sense and to amplify a voltage difference between the common bit line and the selected data line.
4. The nonvolatile memory device of claim 3 , wherein the sense amplification circuit senses data stored in a selected scalable two transistor memory cell and writes data to be written to the selected scalable two transistor memory cell in a write operation.
5. The nonvolatile memory device of claim 3 , wherein the sense amplification circuit senses data stored in a selected scalable two transistor memory cell and outputs the sensed data to outside the nonvolatile memory device in a read operation, and
wherein the sensed data is outputted to the outside the nonvolatile memory device, at the same time, is restored in the selected scalable two transistor memory cell.
6. The nonvolatile memory device of claim 4 , wherein the sense amplification circuit supplies a bias current to the selected scalable two transistor memory cell in sensing data stored in a selected scalable two transistor memory cell.
7. The nonvolatile memory device of claim 3 ,
wherein the sense amplification circuit includes a bias current supply part to supply a bias current to the selected scalable two transistor memory cell in a read/write operation.
8. The nonvolatile memory device of claim 7 , wherein bulk regions of read transistors in the plurality of scalable two transistor memory cells are electrically separated from a bulk region of the bias current supply part in the sense amplification circuit.
9. The nonvolatile memory device of claim 8 , wherein a sense node voltage distribution of the plurality of scalable two transistor memory cells is verified by controlling a voltage applied to bulk regions of the read transistors of the plurality of scalable two transistor memory cells.
10. A nonvolatile memory device comprising:
a plurality of data line pairs;
a plurality of bit lines arranged between each pair of data lines;
a plurality of scalable two transistor memory cells, each memory cell including a write transistor and a read transistor arranged to share a bit line arranged between each pair of data lines;
a plurality of data line selectors corresponding to each pair of the data lines, each of the data line selectors selecting one data line among a corresponding data line pair; and
a plurality of sense amplifiers each corresponding to the data line selectors, each of the sense amplifiers sensing and amplifying a voltage difference between the selected data line and a corresponding bit line.
11. The nonvolatile memory device of claim 10 , wherein scalable two transistor memory cells connected to each of the data line pairs are classified into a first group and a second group, and
wherein scalable two transistor memory cells of the first group are respectively connected to a first group of control lines, and
wherein scalable two transistor memory cells of the second group are respectively connected to a second group of control lines, and
wherein the control lines of the first and second groups are alternately arranged.
12. The nonvolatile memory device of claim 10 , wherein each of the sense amplifiers senses data stored in a selected scalable two transistor memory cell and then writes data to be written to the selected scalable two transistor memory cell in a write operation.
13. The nonvolatile memory device of claim 10 , wherein each of the sense amplifiers senses data stored in the selected scalable two transistor memory and outputs the sensed data to outside the nonvolatile memory device, and
wherein the sensed data is outputted to the outside the nonvolatile memory device, and at the same time, is restored in the selected scalable two transistor memory cell in a read operation.
14. The nonvolatile memory device of claim 12 , wherein each of the sense amplifiers supplies a bias current to the selected scalable two transistor memory cell in sensing data stored in the selected scalable two transistor memory cell.
15. The nonvolatile memory device of claim 10 , wherein each of the scalable two transistor memory cells includes a read transistor and a write transistor, and
wherein each of the sense amplifiers includes a bias current supply part to supply a bias current to the selected scalable two transistor memory cell in a read/write operation.
16. The nonvolatile memory device of claim 15 , wherein bulk regions of read transistors in the scalable two transistor memory cells are electrically separated from a bulk region of the bias current supply part of each of the sense amplifiers.
17. The nonvolatile memory device of claim 16 , wherein a sense node voltage distribution of the scalable two transistor memory cells is verified by controlling a voltage applied to bulk regions of the read transistors of the scalable two transistor memory cells.