X-direction divided sub-block mode in NAND
A memory system having an x-direction (bit line direction) divided sub-block mode. Each block is divided in a y-direction and in the x-direction into a number of groups of contiguous NAND strings that are referred to as XY sub-blocks. The memory system performs a memory operation in parallel in multiple XY sub-blocks in a block while inhibiting the memory operation in the other XY sub-blocks in the block. Each XY sub-block for which the memory operation is performed has its NAND strings connected to a different set of contiguous bit lines. In an aspect the memory operation is a program operation with selected memory cells in each of the multiple XY sub-blocks programmed in parallel while inhibiting programming of all memory cells in all other XY sub-blocks in the block. In one aspect, the memory operation is an erase operation.
1. An apparatus comprising:
a three-dimensional memory structure having a plurality of blocks, each block having a plurality of word lines and select lines, the select lines including a plurality of source side select lines and a plurality of drain side select lines, each block having NAND strings extending in a z-direction through the block, each NAND string having memory cells and select transistors, each word line connected to all of the NAND strings of the block, each select line connected to select transistors on a set of the NAND strings that comprise an XY sub-block, each block having one or more source lines connected to a source end of the NAND strings of a block;
bit lines extending across the plurality of blocks in an x-direction, wherein the XY sub-blocks have a plurality of groups of XY sub-blocks with a drain end of the NAND strings of each group of XY sub-blocks being connected to a different group of contiguous bit lines; and
one or more control circuits in communication with the memory structure and the bit lines, wherein the one or more control circuits are configured to:
perform a program operation in multiple XY sub-blocks in a particular block in parallel while inhibiting the program operation in all other XY sub-blocks in the particular block, including program selected memory cells in each of the multiple XY sub-blocks in parallel while inhibiting programming of all memory cells in all other XY sub-blocks in the particular block, wherein each XY sub-block of the multiple XY sub-blocks has the drain end of its NAND strings connected to a different group of contiguous bit lines.
2. The apparatus of claim 1 , wherein the one or more control circuits are configured to:
apply a channel inhibit voltage to the one or more source lines of the particular block;
apply a cutoff voltage to the source side select lines of the multiple XY sub-blocks to electrically disconnect the one or more source lines from NAND channels in the multiple XY sub-blocks; and
apply a voltage to the source side select lines of all other XY sub-blocks in the particular block to pass the channel inhibit voltage from the one or more source lines to channels of NAND strings in all the other XY sub-blocks in the particular block to prevent programming in all the other XY sub-blocks in the particular block.
3. The apparatus of claim 2 , wherein:
the one or more control circuits are configured to:
apply a program voltage to a selected word line in the particular block; and
apply a boosting voltage to unselected word lines in the particular block; and
the channel inhibit voltage is approximately half of a sum of the program voltage and the boosting voltage.
4. The apparatus of claim 3 , wherein:
the voltage applied to the source side select line of all other XY sub-blocks in the particular block has a magnitude that generates gate-induced drain leakage (GIDL) current in source side select transistors in the other XY sub-blocks in the particular block.
5. The apparatus of claim 1 , wherein the one or more source lines of each block comprise:
a first source line associated with a first group of XY sub-blocks whose NAND strings are connected to a first group of contiguous bit lines; and
a second source line associated with a second group of XY sub-blocks whose NAND strings are connected to a second group of contiguous bit lines.
6. The apparatus of claim 1 , wherein the one or more source lines of each block comprise:
a plurality of source lines, wherein each source line is in a different XY sub-block.
7. The apparatus of claim 6 , wherein the one or more control circuits are configured to:
apply a channel inhibit voltage to the source line of each XY sub-block in the particular block to be inhibited from programming;
apply a voltage that is lower than the channel inhibit voltage to the source lines of the multiple XY sub-blocks;
apply a voltage to the source side select lines of the multiple XY sub-blocks to electrically disconnect the source lines of the multiple XY sub-blocks from channels of NAND strings of the multiple XY sub-blocks; and
apply a gate-induced drain leakage (GIDL) voltage to the source side select lines of all other XY sub-blocks in the particular block to pass the channel inhibit voltage from the source lines of the other XY sub-blocks to channels of NAND strings in all the other XY sub-blocks in the particular block.
8. A method for programming NAND memory, the method comprising:
applying a first data pattern to a first set of contiguous bit lines and a second data pattern to a second set of contiguous bit lines connected to a block that comprises NAND strings, wherein the block comprises word lines with each word line connected to each NAND string of the block, wherein the block comprises a first group of XY sub-blocks whose NAND strings are connected to the first set of contiguous bit lines and a second group of XY sub-blocks whose NAND strings are connected to the second set of contiguous bit lines;
applying a program voltage to a selected word line in the block;
applying a boosting voltage to unselected word lines in the block;
applying a channel inhibit voltage to one or more source lines connected to XY sub-blocks to be inhibited from programming;
applying a voltage to a first source side select line connected to source side select gates on NAND strings in a first XY sub-block of the first group of XY sub-blocks and to a second source side select line connected to source side select gates on NAND strings in a second XY sub-block of the second group of XY sub-blocks that allows programming in the first XY sub-block and the second XY sub-block; and
applying a voltage to source side select lines connected to source side select gates on all other NAND strings in the block to pass the channel inhibit voltage from the one or more source lines to channels of the NAND strings in all the other NAND strings in the block to inhibit programming in all other NAND strings in the block.
9. The method of claim 8 , further comprising:
applying the channel inhibit voltage to one or more source lines connected to the first XY sub-block and the second XY sub-block, wherein applying the voltage to the first source side select line and to the second source side select line prevents the channel inhibit voltage from passing from the one or more source lines to the channels of the NAND strings in the first XY sub-block and the second XY sub-block.
10. The method of claim 8 , further comprising:
applying a voltage that is less than the channel inhibit voltage to a first source line of the first XY sub-block and a second source line of the second XY sub-block, wherein applying the voltage to the first source side select line and to the second source side select line prevents the voltage that is less than the channel inhibit voltage from passing from the first source line to the channels of the NAND strings in the first XY sub-block and from the second source line to channels of the NAND strings in the second XY sub-block.
11. A non-volatile storage system, comprising:
a plurality of bit lines including a first contiguous group of bit lines and a second contiguous group of bit lines;
a three-dimensional memory structure having a plurality of blocks, each block having NAND strings extending in a z-direction through the block, each block having a plurality of word lines, each word line connected to all of the NAND strings in the block, each block having one or more source lines, each NAND string having: memory cells, a drain side select gate connected to a bit line of the plurality of bit lines, and a source side select gate, wherein each source side select gate has a control terminal, a first terminal connected to a channel of a NAND string, and a second terminal connected to a source line of the one or more source lines, each block comprises a plurality of source side select lines including:
a first set of source side select lines, each source side select line in the first set connected to the control terminals of source side select gates of a contiguous group of NAND strings of a first set of contiguous groups of NAND strings connected to the first contiguous group of bit lines; and
a second set of source side select lines, each source side select line in the second set connected to the control terminals of source side select gates of a contiguous group of NAND strings of a second set of contiguous groups of NAND strings connected to the second contiguous group of bit lines; and
one or more control circuits in communication with the memory structure and the bit lines, wherein the one or more control circuits are configured to:
apply voltages to the word lines in a selected block, the first contiguous group of bit lines, and the second contiguous group of bit lines to perform a memory operation within the selected block;
apply a channel inhibit voltage to the one or more source lines of the selected block; and
apply voltages to the control terminals and the second terminals of the source side select gates of a first contiguous group of NAND strings in the selected block connected to the first contiguous group of bit lines and to a second contiguous group of NAND strings in the selected block connected to the second contiguous group of bit lines to allow the memory operation in the first contiguous group of NAND strings and the second contiguous group of NAND strings while applying voltages to the control terminals and the second terminals of the source side select gates of all other NAND strings in the selected block connected to the first or second contiguous group of bit lines to prevent the memory operation in all other NAND strings in the selected block connected to the first or second contiguous group of bit lines, including:
apply a voltage to a first source side select line of the first set of source side select lines, the first source side select line connected to the source side select gates of the first contiguous group of NAND strings to cut off the one or more source lines from the channels of the first contiguous group of NAND strings;
apply a voltage to a second source side select line of the second set of source side select lines, the second source side select line connected to the source side select gates of the second contiguous group of NAND strings to cut off the one or more source lines from the channels of the second contiguous group of NAND strings; and
apply a voltage to the source side select lines connected to all other NAND strings in the selected block to pass the channel inhibit voltage from the one or more source lines to all other NAND strings in the selected block.
12. The non-volatile storage system of claim 11 , wherein:
each block comprises a plurality of source lines, including:
a first set of source lines, each source line in the first set of source lines connected to the second terminals of source side select transistors of a contiguous group of NAND strings of a first set contiguous groups of NAND strings connected to the first contiguous group of bit lines; and
a second set of source lines, each source line in the second set connected to the second terminals of source side select transistors of a contiguous group of NAND strings of a second set contiguous groups of NAND strings connected to the second contiguous group of bit lines.
13. The non-volatile storage system of claim 12 , wherein the one or more control circuits are configured to:
apply a channel inhibit voltage to the source line of each contiguous group of NAND strings to be inhibited from programming;
apply a voltage that is lower than the channel inhibit voltage to a first source line connected to the first contiguous group of NAND strings and to a second source line connected to the second contiguous group of NAND strings;
apply a voltage to the source side select line connected to the source side select transistors of the first contiguous group of NAND strings to cut off the first source line from the channels of the first contiguous group of NAND strings;
apply a voltage to the source side select line connected to the source side select transistors of the second contiguous group of NAND strings to cut off the second source line from the channels of the second contiguous group of NAND strings; and
apply a gate-induced drain leakage (GIDL) voltage to the source side select line connected to all other contiguous groups of NAND strings in the selected block to pass the channel inhibit voltage from the one or more source lines to all other contiguous groups of NAND strings in the selected block.
14. An apparatus comprising:
a three-dimensional memory structure having a plurality of blocks, each block having a plurality of word lines and select lines, the select lines including a plurality of source side select lines and a plurality of drain side select lines, each block having NAND strings extending in a z-direction through the block, each NAND string having memory cells and select transistors, each word line connected to all of the NAND strings of the block, each select line connected to select transistors on a set of the NAND strings that comprise an XY sub-block, each block having one or more source lines connected to a source end of the NAND strings of a block;
bit lines extending across the plurality of blocks in an x-direction, wherein the XY sub-blocks have a plurality of groups of XY sub-blocks with a drain end of the NAND strings of each group of XY sub-blocks being connected to a different group of contiguous bit lines; and
one or more control circuits in communication with the memory structure and the bit lines, wherein the one or more control circuits are configured to:
perform an erase operation in multiple XY sub-blocks in a particular block in parallel while inhibiting the erase operation in all other XY sub-blocks in the particular block, including erase the multiple XY sub-blocks in parallel while inhibiting erase in all other XY sub-blocks in the particular block, wherein each XY sub-block of the multiple XY sub-blocks has the drain end of its NAND strings connected to a different group of contiguous bit lines.
15. The apparatus of claim 14 , wherein the one or more source lines of each block comprise:
a plurality of source lines, wherein each source line is in a different XY sub-block.
16. The apparatus of claim 15 , wherein the one or more control circuits are configured to:
float the source line of each XY sub-block in the particular block to be inhibited from erase;
apply an erase voltage to the source lines of the multiple XY sub-blocks;
apply a voltage to the source side select lines of the multiple XY sub-blocks to pass the erase voltage from the source lines of the multiple XY sub-blocks to channels of NAND strings in the multiple XY sub-blocks; and
apply a cutoff voltage to the source side select lines of all other XY sub-blocks in the particular block to electrically disconnect the source lines from the other XY sub-blocks in the particular block.
17. The apparatus of claim 15 , wherein the one or more control circuits are configured to:
ground the source line of each XY sub-block in the particular block to be inhibited from programming;
apply an erase voltage to the source lines of the multiple XY sub-blocks;
apply a voltage to the source side select lines of the multiple XY sub-blocks to pass the erase voltage from the source lines of the multiple XY sub-blocks to channels of NAND strings in the multiple XY sub-blocks; and
apply a cutoff voltage to the source side select lines of all other XY sub-blocks in the particular block to electrically disconnect the source lines from the other XY sub-blocks in the particular block.