Salvaging bad blocks in a memory device
AssigneeMicron Technology, Inc.
InventorsSri Rama Namala, Lu Tong, Kristopher Kopel, Sheng-Huang Lee, Chang H. Siau
Life of this patent
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Abstract
Disclosed in some examples are methods, systems, devices, memory devices, and machine-readable mediums for using a non-defective portion of a block of memory on which there is a defect on a different portion. Rather than disable the entire block, the system may disable only a portion of the block (e.g., a first deck of the block) and salvage a different portion of the block (e.g., a second deck of the block).
Claims20
A memory device comprising:
- a processor;
- a memory, storing instructions, which when executed, causes the processor to perform operations comprising:
- identifying that a first deck of a block of three-dimensional NAND has a defect of a type from an identified list of defect types;
- identifying that a second deck of the block does not have a defect from the identified list of defect types;
- testing the second deck to determine if it meets at least one quality criterion;
- responsive to determining that the second deck meets at least one quality criterion, marking the second deck as salvageable;
- receiving a memory device request;
- identifying a bias voltage for the first deck of the block;
- and
- servicing the memory device request serviced using NAND cells in the second deck, the servicing the memory device request comprising disabling the first deck during the servicing by applying the bias voltage to word lines of the first deck.
A method of operating a memory device, the method comprising:
- identifying that a first deck of a block of three-dimensional NAND of the memory device has a defect of a type from an identified list of defect types;
- identifying that a second deck of the block does not have a defect from the identified list of defect types;
- testing the second deck to determine if it meets at least one quality criterion;
- responsive to determining that the second deck meets at least one quality criterion, marking the second deck as salvageable;
- receiving a memory device request;
- identifying a bias voltage for the first deck of the block;
- and
- servicing the memory device request serviced using NAND cells in the second deck, the servicing the memory device request comprising disabling the first deck during the servicing by applying the bias voltage to word lines of the first deck.
A non-transitory, machine-readable medium, storing instructions, which when executed, causes a hardware processor of a memory device to perform operations comprising:
- identifying that a first deck of a block of three-dimensional NAND has a defect of a type from an identified list of defect types;
- identifying that a second deck of the block does not have a defect from the identified list of defect types;
- testing the second deck to determine if it meets at least one quality criterion;
- responsive to determining that the second deck meets at least one quality criterion, marking the second deck as salvageable;
- receiving a memory device request;
- identifying a bias voltage for the first deck of the block;
- and
- servicing the memory device request serviced using NAND cells in the second deck, the servicing the memory device request comprising disabling the first deck during the servicing by applying the bias voltage to word lines of the first deck.
Dependencies are inferred from the claim text.