Imprint recovery for memory cells
Methods, systems, and devices for imprint recovery for memory cells are described. In some cases, memory cells may become imprinted, which may refer to conditions where a cell becomes predisposed toward storing one logic state over another, resistant to being written to a different logic state, or both. Imprinted memory cells may be recovered using a recovery or repair process that may be initiated according to various conditions, detections, or inferences. In some examples, a system may be configured to perform imprint recovery operations that are scaled or selected according to a characterized severity of imprint, an operational mode, environmental conditions, and other factors. Imprint management techniques may increase the robustness, accuracy, or efficiency with which a memory system, or components thereof, can operate in the presence of conditions associated with memory cell imprinting.
1. A method, comprising:
determining to perform an imprint recovery procedure on a memory cell configured to store one of a set of logic states based at least in part on detecting, for a set of memory cells comprising the memory cell, a quantity of mismatched logic states that satisfies a threshold quantity of mismatched logic states, wherein the imprint recovery procedure is to increase an ability of the memory cell to switch between storing different logic states of the set of logic states; and
applying, to the memory cell and based at least in part on determining to perform the imprint recovery procedure, a set of voltage cycles each comprising a respective first voltage pulse having a first polarity and a respective second voltage pulse having a second polarity.
2. The method of claim 1 , further comprising:
determining, for the set of memory cells comprising the memory cell, that a greater quantity of memory cells of the set of memory cells is imprinted in a first logic state of the set of logic states than in a second logic state of the set of logic states, wherein a voltage pulse for writing the first logic state to the memory cell has the first polarity and a voltage pulse for writing the second logic state to the memory cell has the second polarity; and
configuring the respective first voltage pulse to have a smaller amplitude than the respective second voltage pulse, a shorter duration than the respective second voltage pulse, or both based at least in part on determining that the memory cell is imprinted in the first logic state.
3. The method of claim 1 , further comprising:
identifying the set of memory cells on which to perform the imprint recovery procedure; and
determining a duration, an amplitude, a quantity, or any combination thereof of voltage cycles in the set of voltage cycles based at least in part on a quantity of memory cells included in the set of memory cells, wherein the applying is based at least in part on determining the duration, the amplitude, the quantity, or the combination thereof of the voltage cycles.
4. The method of claim 1 , further comprising:
identifying a severity with which the memory cell is imprinted in a logic state of the set of logic states; and
determining a duration, an amplitude, a quantity, or any combination thereof of voltage cycles in the set of voltage cycles based at least in part on the severity with which the memory cell is imprinted, wherein the applying is based at least in part on determining the duration, the amplitude, the quantity, or the combination thereof of the voltage cycles.
5. The method of claim 1 , further comprising:
identifying an age of a memory device that includes the memory cell; and
determining a duration, an amplitude, a quantity, or any combination thereof of voltage cycles in the set of voltage cycles based at least in part on the age of the memory device, wherein the applying is based at least in part on determining the duration, the amplitude, the quantity, or the combination thereof of the voltage cycles.
6. The method of claim 1 , further comprising:
identifying a temperature of a memory device that includes the memory cell; and
determining a duration, an amplitude, a quantity, or any combination thereof of voltage cycles in the set of voltage cycles based at least in part on the temperature of the memory device, wherein the applying is based at least in part on determining the duration, the amplitude, the quantity, or the combination thereof of the voltage cycles.
7. The method of claim 1 , further comprising:
identifying a first duration of a time window for performing the imprint recovery procedure; and
determining a second duration, an amplitude, a quantity, or any combination thereof of voltage cycles in the set of voltage cycles based at least in part on the first duration of the time window for performing the imprint recovery procedure, wherein the applying is based at least in part on determining the second duration, the amplitude, the quantity, or the combination thereof of the voltage cycles.
8. The method of claim 1 , further comprising:
identifying an amount of power available for performing the imprint recovery procedure; and
determining a duration, an amplitude, a quantity, or any combination thereof of voltage cycles in the set of voltage cycles based at least in part on the amount of power available for performing the imprint recovery procedure, wherein the applying is based at least in part on determining the duration, the amplitude, the quantity, or the combination thereof of the voltage cycles.
9. The method of claim 1 , wherein:
the respective first voltage pulse and the respective second voltage pulse have at least one of a same duration or a same amplitude.
10. The method of claim 1 , wherein:
the respective first voltage pulse and the respective second voltage pulse have at least one of a different duration or a different amplitude.
11. The method of claim 1 , wherein applying a voltage cycle of the set of voltage cycles comprises:
reading a first logic state of the set of logic states from the memory cell; and
writing a second logic state of the set of logic states to the memory cell.
12. The method of claim 1 , wherein:
the memory cell comprises a ferroelectric memory cell; and
the imprint recovery procedure is to increase the ability of the memory cell to switch between storing a first logic state of the set of logic states and storing a second logic state of the set of logic states based at least in part on altering a configuration of electrostatic domains within the ferroelectric memory cell.
13. An apparatus, comprising:
a memory cell configured to store one of a set of logic states; and
a controller configured to cause the apparatus to:
determine to perform an imprint recovery procedure on the memory cell based at least in part on detecting, for a set of memory cells comprising the memory cell, a quantity of mismatched logic states that satisfies a threshold quantity of mismatched logic states, wherein the imprint recovery procedure is to increase an ability of the memory cell to switch between storing different logic states of the set of logic states; and
apply, to the memory cell and based at least in part on determining to perform the imprint recovery procedure, a set of voltage cycles each comprising a respective first voltage pulse having a first polarity and a respective second voltage pulse having a second polarity.
14. The apparatus of claim 13 , wherein:
the respective first voltage pulse and the respective second voltage pulse have at least one of a same duration or a same amplitude.
15. The apparatus of claim 13 , wherein:
the respective first voltage pulse and the respective second voltage pulse have at least one of a different duration or a different amplitude.
16. The apparatus of claim 13 , wherein:
an amplitude or a quantity of voltage cycles in the set of voltage cycles is based at least in part on a severity with which the memory cell is imprinted in a logic state of the set of logic states, an age of a memory device that includes the memory cell, a temperature of the memory device that includes the memory cell, an amount of time available for performing the imprint recovery procedure, an amount of power available for performing the imprint recovery procedure, a quantity of memory cells subject to the imprint recovery procedure, or any combination thereof.
17. A non-transitory computer-readable medium storing code comprising instructions which, when executed by a processor of an electronic device, cause the electronic device to:
determine to perform an imprint recovery procedure on a memory cell configured to store one of a set of logic states based at least in part on detecting, for a set of memory cells comprising the memory cell, a quantity of mismatched logic states that satisfies a threshold quantity of mismatched logic states, wherein the imprint recovery procedure is to increase an ability of the memory cell to switch between storing different logic states of the set of logic states; and
apply, to the memory cell and based at least in part on determining to perform the imprint recovery procedure, a set of voltage cycles each comprising a respective first voltage pulse having a first polarity and a respective second voltage pulse having a second polarity.
18. The non-transitory computer-readable medium of claim 17 , wherein:
the respective first voltage pulse and the respective second voltage pulse have at least one of a same duration or a same amplitude.
19. The non-transitory computer-readable medium of claim 17 , wherein:
the respective first voltage pulse and the respective second voltage pulse have at least one of a different duration or a different amplitude.
20. The non-transitory computer-readable medium of claim 17 , wherein:
an amplitude or a quantity of voltage cycles in the set of voltage cycles is based at least in part on a severity with which the memory cell is imprinted in a logic state of the set of logic states, an age of a memory device that includes the memory cell, a temperature of the memory device that includes the memory cell, an amount of time available for performing the imprint recovery procedure, an amount of power available for performing the imprint recovery procedure, a quantity of memory cells subject to the imprint recovery procedure, or any combination thereof.