Compensation of non-volatile memory chip non-idealities by program pulse adjustment
View Patent ↗To program a set of non-volatile storage elements, a set of programming pulses are applied to the control gates (or other terminals) of the non-volatile storage elements. The programming pulses have pulse widths that vary as a function of simulated pulse magnitude data. The programming pulses can also have pulse magnitudes that vary based on measurements taken while testing the set of non-volatile storage elements. In one embodiment, the pulse widths are determined after simulation performed prior to fabrication of the non-volatile storage elements. In another embodiment, the pulse magnitudes are calculated after fabrication of the non-volatile storage elements.
1. A method for programming non-volatile storage, comprising:
determining pulse widths for a plurality of memory devices including determining pulse widths for multiple programming pulses of a programming signal based on a simulation of said plurality of memory devices;
calculating pulse magnitudes for said multiple programming pulses of said programming signal for a particular memory device from said plurality of memory devices, said calculating is performed subsequent to fabrication of said particular memory device; and
applying said programming signal to said particular memory device.
2. A method according to claim 1 , wherein:
said step of applying said programming signal is concurrently performed for multiple non-volatile storage elements of said particular memory device.
3. A method according to claim 1 , wherein:
said step of determining pulse widths includes determining pulse widths based on pulse magnitudes observed during simulation of said plurality of memory devices; and
said step of applying said programming signal includes applying multiple programming pulses with pulse widths that vary as a function of said pulse magnitudes observed during simulation.
4. A method according to claim 1 , wherein:
said step of calculating pulse magnitudes includes calculating pulse magnitudes for individual pulses of said multiple programming pulses.
5. A method according to claim 1 , wherein:
said step of calculating pulse magnitudes includes calculating pulse magnitudes based on a physical test of said particular memory device.
6. A method according to claim 1 , wherein:
said step of calculating pulse magnitudes includes calculating pulse magnitudes based on measured changes in threshold voltage for said particular memory device; and
said step of applying said programming signal includes applying multiple programming pulses with pulse magnitudes that vary as a function of said measured changes in threshold voltage for said particular memory device.
7. A non-volatile storage system, comprising:
a particular memory device from a plurality of memory devices; and
one or more managing circuits in communication with said particular memory device, said one or more managing circuits program said particular memory device by applying programming pulses with pulse widths determined based on a simulation of said plurality of memory devices, said one or more managing circuits apply said programming pulses with pulse magnitudes calculated subsequent to fabrication of said particular memory device.
8. A non-volatile storage system according to claim 7 , wherein:
said one or more managing circuits concurrently apply said programming pulses to multiple non-volatile storage elements of said particular memory device.
9. A non-volatile storage system according to claim 7 , wherein:
said one or more managing circuits apply said programming pulses with pulse widths determined based on pulse magnitudes observed during simulation of said plurality of memory devices; and
said one or more managing circuits apply said programming pulses with pulse widths that vary as a function of said pulse magnitudes observed during simulation.
10. A non-volatile storage system according to claim 7 , wherein:
said one or more managing circuits apply said programming pulses with pulse magnitudes calculated for individual pulses of said programming pulses.
11. A non-volatile storage system according to claim 7 , wherein:
said one or more managing circuits apply said programming pulses with pulse magnitudes calculated based on a physical test of said particular memory device.
12. A non-volatile storage system according to claim 7 , wherein:
said one or more managing circuits apply said programming pulses with pulse magnitudes calculated based on measured changes in threshold voltage for said particular memory device; and
said one or more managing circuits apply said programming pulses with pulse magnitudes that vary as a function of said measured changes in threshold voltage for said particular memory device.