Isolating problematic memory planes to avoid neighbor plan disturb
Apparatuses and techniques are described for detecting and isolating defective blocks of memory cells in a multi-plane operation such as program or erase. In one aspect, a program operation begins in a multi-plane mode, for one block in each plane. If fewer than all blocks complete programming by the time a trigger number of program loops have been performed, one or more unpassed blocks are programmed further, one at a time, in a single plane mode. If the one or more unpassed blocks do not complete programming when a maximum allowable number of program loops have been performed, they are marked as bad blocks and disabled from further operations. In another aspect, when a trigger number of program loops have been performed, one or more unpassed blocks are subject to a word line leakage detection operation.
1. An apparatus, comprising:
a control circuit configured to connect to a word line in each plane of a plurality of planes, each word line is connected to a respective set of memory cells, to perform a program operation for the respective sets of memory cells, the control circuit is configured to:
apply one or more common program pulses to each word line in a multi-plane program mode;
determine that at least a first set of memory cells has completed programming when a first number of common program pulses have been applied;
in response to determining that at least the first set of memory cells has completed programming, set a trigger number according to the first number;
determine that one or more respective sets of memory cells have not completed programming when the trigger number of common program pulses have been applied; and
in response to the determining that the one or more respective sets of memory cells have not completed programming when the trigger number of common program pulses have been applied, apply program pulses to word lines of the one or more respective sets of memory cells which have not completed programming in a single-plane program mode, one respective set of memory cells at a time, until no more than a maximum allowable number of program pulses have been applied.
2. The apparatus of claim 1 , wherein the respective sets of memory cells are in respective blocks, and control circuit is configured to:
set a fail status for, and disabling for use in future operations, respective blocks of any respective set of memory cells which has not completed programming when the maximum allowable number of program pulses have been applied; and
set a pass status for respective blocks of any respective set of memory cells which has completed programming no later than when the maximum allowable number of program pulses have been applied.
3. The apparatus of claim 1 , wherein:
the common program pulses in the multi-plane mode and the program pulses in the single-plane mode are applied by a single voltage driver.
4. The apparatus of claim 1 , wherein:
the programming of the respective sets of memory cells comprises single bit per cell programming.
5. The apparatus of claim 1 , wherein:
the control circuit is configured to set the trigger number to the sum of the first number and a predetermined number.
6. The apparatus of claim 1 , wherein:
the maximum allowable number is an increasing function of a program loop at which a set of memory cells of the respective sets of memory cells first completes programming.
7. The apparatus of claim 1 , wherein:
the control circuit is configured to set the maximum allowable number based on memory hole widths corresponding to the respective word lines.
8. A method of performing a program operation, comprising:
applying one or more common program pulses to a word line of each plane in a multi-plane program mode of a multi-plane in which each word line is connected to a respective set of memory cells;
determining that at least a first set of memory cells has completed programming when a first number of common program pulses have been applied;
in response to determining that at least the first set of memory cells has completed programming, setting a trigger number according to the first number;
determining that one or more respective sets of memory cells have not completed programming when the trigger number of common program pulses have been applied; and
in response to the determining that the one or more respective sets of memory cells have not completed programming when the trigger number of common program pulses have been applied, applying program pulses to word lines of the one or more respective sets of memory cells which have not completed programming in a single-plane program mode, one respective set of memory cells at a time, until no more than a maximum allowable number of program pulses have been applied.
9. The method of claim 8 , further comprising:
setting a fail status for, and disabling for use in future operations, respective blocks of any respective set of memory cells which has not completed programming when the maximum allowable number of program pulses have been applied; and
setting a pass status for respective blocks of any respective set of memory cells which has completed programming no later than when the maximum allowable number of program pulses have been applied.
10. The method of claim 8 , further comprising:
applying the common program pulses in the multi-plane mode and applying the program pulses in the single-plane mode using single voltage driver.
11. The method of claim 8 , wherein the programming of the respective sets of memory cells comprises single bit per cell programming.
12. The method of claim 8 , further comprising:
setting the trigger number to a sum of the first number and a predetermined number.
13. The method of claim 1 , further comprising:
increasing the maximum allowable number as a function of a program loop at which a set of memory cells of the respective sets of memory cells first completes programming.
14. An apparatus, comprising:
a control circuit configured to connect to a word line in each plane of a plurality of planes, each word line is connected to a respective set of memory cells formed in memory holes that vary in width, to perform a program operation for the respective sets of memory cells, the control circuit is configured to:
apply one or more common program pulses to each word line in a multi-plane program mode;
determine that one or more respective sets of memory cells have not completed programming when a trigger number of common program pulses have been applied; and
in response to the determining that the one or more respective sets of memory cells have not completed programming when the trigger number of common program pulses have been applied, apply program pulses to word lines of the one or more respective sets of memory cells which have not completed programming in a single-plane program mode, one respective set of memory cells at a time, until no more than a maximum allowable number of program pulses have been applied, at least one of the trigger number and the maximum allowable number based on the memory hole widths corresponding to the respective word lines.
15. The apparatus of claim 14 , wherein the respective sets of memory cells are in respective blocks, and control circuit is configured to:
set a fail status for, and disabling for use in future operations, respective blocks of any respective set of memory cells which has not completed programming when the maximum allowable number of program pulses have been applied; and
set a pass status for respective blocks of any respective set of memory cells which has completed programming no later than when the maximum allowable number of program pulses have been applied.
16. The apparatus of claim 14 , wherein:
the common program pulses in the multi-plane mode and the program pulses in the single-plane mode are applied by a single voltage driver.
17. The apparatus of claim 14 , wherein:
the programming of the respective sets of memory cells comprises single bit per cell programming.
18. The apparatus of claim 14 , wherein:
the maximum allowable number is an increasing function of a program loop at which a set of memory cells of the respective sets of memory cells first completes programming.
19. The apparatus of claim 14 , wherein:
the control circuit is configured to set the trigger number to the sum of the first number and a predetermined number and set the maximum allowable number based on the memory hole widths corresponding to the respective word lines.