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).
Claims17
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 a first identified list of defect types;
- identifying that a second deck of the block does not have a defect from the first identified list of defect types;
- testing the second deck by:
- storing a specified value in memory cells of the second deck;
- reading a value from the second deck;
- determining that a number of errors during the reading the value of the second deck is below a threshold number of errors;
- and
- responsive to determining that the number of errors is below the threshold number of errors, marking the second deck as salvageable;
- receiving a request to perform an operation on the second deck;
- identifying a bias voltage for the first deck of the block based upon the type of operation;
- and
- performing the operation on the second deck, the performing the operation comprising disabling the first deck during the operation by applying a bias voltage to word lines of the first deck.
A method for salvaging portions of defective blocks of a memory device, the method comprising:
- identifying that a first deck of a block of three-dimensional NAND memory cells has a defect of a type from a first identified list of defect types;
- identifying that a second deck of the block does not have a defect from the first identified list of defect types;
- testing the second deck by:
- storing a specified value in memory cells of the second deck;
- reading a value from the second deck;
- determining that a number of errors during the reading the value of the second deck is below a threshold number of errors;
- and
- responsive to determining that the number of errors is below the threshold number of errors, marking the second deck as salvageable;
- receiving a request to perform an operation on the second deck;
- identifying a bias voltage for the first deck of the block based upon the type of operation;
- and
- performing the operation on the second deck, the performing the operation comprising disabling the first deck during the operation by applying a bias voltage to word lines of the first deck.
A non-transitory machine-readable storage medium, storing instructions, which when executed, cause a machine to perform operations comprising:
- identifying that a first deck of a block of three-dimensional NAND has a defect of a type from a first identified list of defect types;
- identifying that a second deck of the block does not have a defect from the first identified list of defect types;
- testing the second deck by:
- storing a specified value in memory cells of the second deck;
- reading a value from the second deck;
- determining that a number of errors during the reading the value of the second deck is below a threshold number of errors;
- and
- responsive to determining that the number of errors is below the threshold number of errors, marking the second deck as salvageable;
- receiving a request to perform an operation on the second deck;
- identifying a bias voltage for the first deck of the block based upon the type of operation;
- and
- performing the operation on the second deck, the performing the operation comprising disabling the first deck during the operation by applying a bias voltage to word lines of the first deck.
Dependencies are inferred from the claim text.