Techniques for refreshing a semiconductor memory device
Techniques for refreshing a semiconductor memory device are disclosed. In one particular exemplary embodiment, the techniques may be realized as a method for refreshing a semiconductor memory device may include applying a plurality of voltage potentials to a memory cell in an array of memory cells. Applying a plurality of voltage potentials to the memory cell may include applying a first voltage potential to a first region of the memory cell via a respective source line of the array. Applying a plurality of voltage potentials to the memory cells may also include applying a second voltage potential to a second region of the memory cell via a respective local bit line and a respective selection transistor of the array. Applying a plurality of voltage potentials to the memory cells may further include applying a third voltage potential to a respective word line of the array, wherein the word line may be spaced apart from and capacitively to a body region of the memory cell that may be electrically floating and disposed between the first region and the second region. Applying a plurality of voltage potentials to the memory cells may further include applying a fourth voltage potential to a third region of the memory cell via a respective carrier injection line of the array.
1. A method for refreshing a semiconductor memory device comprising the steps of:
applying a plurality of voltage potentials to a memory cell in an array of memory cells, wherein applying a plurality of voltage potentials to the memory cell comprises:
applying a first voltage potential to a first region of the memory cell via a respective source line of the array;
applying a second voltage potential to a second region of the memory cell via a respective local bit line and a respective selection transistor of the array;
applying a third voltage potential to a respective word line of the array, wherein the word line is spaced apart from and capacitively to a body region of the memory cell that is electrically floating and disposed between the first region and the second region;
applying a fourth voltage potential to a third region of the memory cell via a respective carrier injection line of the array; and
maintaining the first voltage potential applied to the first region at a constant level via the respective source line during the refresh of the semiconductor memory device.
2. The method according to claim 1 , wherein the respective local bit line is coupled to a multiplexer.
3. The method according to claim 2 , wherein the multiplexer is coupled to a global bit line.
4. The method according to claim 2 , wherein the multiplexer comprises at least one masking transistor coupled to the respective local bit line.
5. The method according to claim 4 , wherein the multiplexer further comprises at least one hold transistor coupled to the respective local bit line.
6. The method according to claim 5 , wherein the respective selection transistor is coupled to the at least one mask transistor and the at least one hold transistor.
7. The method according to claim 1 , further comprising applying a selection control signal to the respective selection transistor to activate the respective selection transistor.
8. The method according to claim 7 , further comprising increasing the second voltage potential applied to the respective local bit line from the second voltage potential applied to the respective local bit line during a hold operation via the activated respective selection transistor.
9. The method according to claim 1 , further comprising increasing the fourth voltage potential applied to the respective carrier injection line from the fourth voltage potential applied to the respective carrier injection line during a hold operation.
10. The method according to claim 1 , further comprising applying decoupling control signals to the respective selection transistor to deactivate the respective selection transistor.
11. The method according to claim 10 , the respective local bit line is electrically floating after the respective selection transistor is deactivated.
12. The method according to claim 1 , further comprising increasing the third voltage potential applied to the respective word line from the third voltage potential applied to the respective word line during a hold operation in order to perform a read operation.
13. The method according to claim 12 , wherein the increase in the third voltage potential activates the memory cell to decrease the second voltage potential applied to the respective local bit line.
14. The method according to claim 1 , further comprising decreasing the third voltage potential applied to the respective word line from the third voltage potential applied to the respective word line during a write logic low operation to perform a write logic high operation.
15. The method according to claim 14 , wherein the third voltage potential applied to the respective word line during the write logic high operation is higher than the third voltage potential applied to the respective word line during a hold operation.
16. The method according to claim 1 , further comprising applying a coupling control signals to the respective selection transistor to activate the respective selection transistor in order to perform an end to a write logic high operation.
17. The method according to claim 16 , further comprising discharging the second voltage potential applied to the respective local bit line to forward bias a junction between the second region and the third region.
18. The method according to claim 1 , further comprising decreasing the fourth voltage potential applied to the respective carrier injection line from the fourth voltage potential applied to the respective carrier injection line during a write logic high operation to perform a hold operation.
19. The method according to claim 1 , further comprising decreasing the second voltage potential applied to the respective local bit line from the second voltage potential applied to the respective local bit line during a write logic high operation to perform a hold operation.