Abstract: Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. A binary search may be performed.

Abstract: A non-volatile memory has its cells' thresholds programmed within any one of a first set of voltage bands partitioned by a first set of reference thresholds across a threshold window. Hard bits are obtained when read relative to the first set of reference thresholds. The cells are read at a higher resolution relative to a second set of reference thresholds so as to provide additional soft bits for error correction. The soft bits are generated by a combination of a first modulation of voltage on a current word line WLn and a second modulation of voltage on an adjacent word line WLn+1, as in a reading scheme known as “Direct-Lookahead (DLA)”.

Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential.

Abstract: Data, normally read using a page-by page read process, can be recovered from memory cells connected to a broken word line by performing a sequential read process. To determine whether a word line is broken, both a page-by page read process and a sequential read process are performed. The results of both read processes are compared. If the number of mismatches between the two read processes is greater than a threshold, it is concluded that there is a broken word line.

Abstract: A set of reliability metrics is provided for use by an iterative probabilistic decoding process for non-volatile storage. A plurality of sense operations are performed on at least one set of non-volatile storage elements which are programmed to a plurality of programming states. A set of reliability metrics such as logarithmic likelihood ratios is provided based on the sense operations. The set of reliability metrics is can be used by an iterative probabilistic decoding process in determining a programming state of at least one non-volatile storage element based on at least one subsequent sense operation involving the at least one non-volatile storage element. The plurality of sense operations can be performed at different ages (e.g., number of program/erase cycles) of the at least one set of non-volatile storage elements and the set of reliability metrics can be based on an average over the different ages.

Abstract: Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. A binary search may be performed.

Abstract: Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. A binary search may be performed.

Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential.

Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line.

Abstract: A system and methods to find the threshold voltage distribution across a set of nonvolatile memory cells, such that embodiments may incorporate this distribution information into calculations that may change the read compare voltages used to read the memory cells, while ensuring adequate separation in read voltage between different data states at which the memory cells may be read.

Abstract: A non-volatile memory has its cells' thresholds programmed within any one of a first set of voltage bands partitioned by a first set of reference thresholds across a threshold window. Hard bits are obtained when read relative to the first set of reference thresholds. The cells are read at a higher resolution relative to a second set of reference thresholds so as to provide additional soft bits for error correction. The soft bits are generated by a combination of a first modulation of voltage on a current word line WLn and a second modulation of voltage on an adjacent word line WLn+1, as in a reading scheme known as “Direct-Lookahead (DLA)”.

Abstract: Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. A binary search may be performed.

Abstract: A set of reliability metrics is provided for use by an iterative probabilistic decoding process for non-volatile storage. A plurality of sense operations are performed on at least one set of non-volatile storage elements which are programmed to a plurality of programming states. A set of reliability metrics such as logarithmic likelihood ratios is provided based on the sense operations. The set of reliability metrics is can be used by an iterative probabilistic decoding process in determining a programming state of at least one non-volatile storage element based on at least one subsequent sense operation involving the at least one non-volatile storage element. The plurality of sense operations can be performed at different ages (e.g., number of program/erase cycles) of the at least one set of non-volatile storage elements and the set of reliability metrics can be based on an average over the different ages.

Abstract: In sensing a group of cells in a multi-state nonvolatile memory, multiple sensing cycles relative to different demarcation threshold levels are needed to resolve all possible multiple memory states. Each sensing cycle has a sensing pass. It may also include a pre-sensing pass or sub-cycle to identify the cells whose threshold voltages are below the demarcation threshold level currently being sensed relative to. These are higher current cells which can be turned off to achieve power-saving and reduced source bias errors. The cells are turned off by having their associated bit lines locked out to ground. A repeat sensing pass will then produced more accurate results. Circuitry and methods are provided to selectively enable or disable bit-line lockouts and pre-sensing in order to improving performance while ensuring the sensing operation does not consume more than a maximum current level.

Abstract: Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time.

Abstract: A non-volatile memory has its cells' thresholds programmed within any one of a first set of voltage bands partitioned by a first set of reference thresholds across a threshold window. Hard bits are obtained when read relative to the first set of reference thresholds. The cells are read at a higher resolution relative to a second set of reference thresholds so as to provide additional soft bits for error correction. The soft bits are generated by a combination of a first modulation of voltage on a current word line WLn and a second modulation of voltage on an adjacent word line WLn+1, as in a reading scheme known as “Direct-Lookahead (DLA)”.

Abstract: To program a set of non-volatile storage elements, a set of programming pulses are applied to the control gates (or other terminals) of the non-volatile storage elements. The programming pulses have pulse widths that vary as a function of simulated pulse magnitude data. The programming pulses can also have pulse magnitudes that vary based on measurements taken while testing the set of non-volatile storage elements. In one embodiment, the pulse widths are determined after simulation performed prior to fabrication of the non-volatile storage elements. In another embodiment, the pulse magnitudes are calculated after fabrication of the non-volatile storage elements.

Abstract: Data stored in non-volatile storage is decoded using iterative probabilistic decoding and multiple read operations to achieve greater reliability. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding read data of a set of non-volatile storage element. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. If convergence does not occur, e.g., within a set time period, the state of the non-volatile storage element is sensed again, current values of the reliability metrics in the decoder are adjusted, and the decoding again attempts to converge.

Abstract: A non-volatile memory fabrication process includes the formation of a complete memory cell layer stack before isolation region formation. The memory cell layer stack includes an additional place holding control gate layer. After forming the layer stack columns, the additional control gate layer will be incorporated between an overlying control gate layer and underlying intermediate dielectric layer. The additional control gate layer is self-aligned to isolation regions between columns while the overlying control gate layer is etched into lines for contact to the additional control gate layer. In one embodiment, the placeholder control gate layer facilitates a contact point to the overlying control gate layer such that contact between the control gate layers and the charge storage layer is not required for select gate formation.

Abstract: Shifts in the apparent charge stored on a floating gate (or other charge storing element) of a non-volatile memory cell can occur because of the coupling of an electric field based on the charge stored in adjacent floating gates (or other adjacent charge storing elements). The problem occurs most pronouncedly between sets of adjacent memory cells that have been programmed at different times. To account for this coupling, the read process for a particular memory cell will provide compensation to an adjacent memory cell in order to reduce the coupling effect that the adjacent memory cell has on the particular memory cell.