Dynamic reconditioning of charge trapped based memory
AssigneeSanDisk Technologies LLC
InventorsNian Niles Yang, James Fitzpatrick, Jiahui Yuan
Life of this patent
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Abstract
A storage device with a charge trapping (CT) based memory may include improved data retention (DR) performance. The CT memory may be 3D memory that uses a charge storage layer for storing charge may have unique data retention behavior. Memory blocks using a charge storage layer may be dynamically detected and reconditioned and re-programmed to improve memory characteristics, such as data retention. The reconditioning may include a dedicated erase cycle for a block that improves the data retention.
Claims18
A method for refreshing charge trap flash memory, the method comprising:
- detecting a data retention voltage shift in a portion of the charge trap flash memory;
- relocating data stored at the detected portion of the charge trap flash memory;
- reconditioning the detected portion of the charge trap flash memory by performing an erase cycle of the portion of the charge trap flash memory;
- and
- reprogramming, after the reconditioning, the detected portion of the charge trap flash memory with the previously relocated data or new data.
A storage device comprising:
- a memory comprising memory blocks for data storage, wherein the memory comprises a dielectric layer for charge trapping;
- a controller coupled with the memory for programming the memory blocks;
- and
- detection circuitry that dynamically detects data retention shifts of the memory cell voltage, and
- recondition circuitry that subsequently reconditions one or more of the memory blocks by performing a dedicated erase program cycle for the one or more memory blocks to improve data retention for charge trapped in the dielectric layer.
Dependencies are inferred from the claim text.