Abstract: An erase operation for non-volatile memory includes first and second phases. The first phase applies a series of voltage pulses to a substrate, where each erase pulse is followed by a verify operation. The verify operation uses a verify level which is offset higher from a final desired threshold voltage level. The erase pulses step up in amplitude until a maximum level is reached, at which point additional erase pulses at the maximum level are applied. The first phase ends when the verify operation passes. The second phase applies one or more extra erase pulses which are higher in amplitude than the last erase pulse in the first phase and which are not followed by a verify operation. This avoids the need to perform a verify operation at deep, negative threshold voltages levels, which can cause charge trapping which reduces write-erase endurance, while still achieving the desired deep erase.

Abstract: A system for programming non-volatile storage is proposed that reduces the impact of interference from the boosting of neighbors. Memory cells are divided into two or more groups. In one example, the memory cells are divided into odd and even memory cells; however, other groupings can also be used. Prior to a first trigger, a first group of memory cells are programmed together with a second group of memory cells using a programming signal that increases over time. Subsequent to the first trigger and prior to a second trigger, the first group of memory cells are programmed separately from the second group of memory cells using a programming signal that has been lowered in magnitude in response to the first trigger. Subsequent to the second trigger, the first group of memory cells are programmed together with the second group of memory cells with the programming signal being raised in response to the second trigger.

Abstract: An erase operation for non-volatile memory includes first and second phases. The first phase applies a series of voltage pulses to a substrate, where each erase pulse is followed by a verify operation. The verify operation uses a verify level which is offset higher from a final desired threshold voltage level. The erase pulses step up in amplitude until a maximum level is reached, at which point additional erase pulses at the maximum level are applied. The first phase ends when the verify operation passes. The second phase applies one or more extra erase pulses which are higher in amplitude than the last erase pulse in the first phase and which are not followed by a verify operation. This avoids the need to perform a verify operation at deep, negative threshold voltages levels, which can cause charge trapping which reduces write-erase endurance, while still achieving the desired deep erase.

Abstract: When erasing non-volatile storage, a verification process is used between erase operations to determine whether the non-volatile storage has been successfully erased. The verification process includes separately performing verification for different subsets of the non-volatile storage elements.

Abstract: Program disturb is reduced in a non-volatile storage system during a program operation for a selected word line by initially using a pass voltage with a lower amplitude on word lines which are adjacent to the selected word line. This helps reduce charge trapping at floating gate edges, which can widen threshold voltage distributions with increasing program-erase cycles. When program pulses of higher amplitude are applied to the selected word line, the pass voltage switches to a higher level to provide a sufficient amount of channel boosting. The switch to a higher pass voltage can be triggered by a specified program pulse being applied or by tracking lower state storage elements until they reach a target verify level. The amplitude of the program voltage steps down when the pass voltage steps up, to cancel out capacitive coupling to the selected storage elements from the change in the pass voltage.

Abstract: When erasing non-volatile storage, a verification process is used between erase operations to determine whether the non-volatile storage has been successfully erased. The verification process includes separately performing verification for different subsets of the non-volatile storage elements.

Abstract: Program disturb is reduced in a non-volatile storage system during a program operation for a selected word line by initially using a pass voltage with a lower amplitude on word lines which are adjacent to the selected word line. This helps reduce charge trapping at floating gate edges, which can widen threshold voltage distributions with increasing program-erase cycles. When program pulses of higher amplitude are applied to the selected word line, the pass voltage switches to a higher level to provide a sufficient amount of channel boosting. The switch to a higher pass voltage can be triggered by a specified program pulse being applied or by tracking lower state storage elements until they reach a target verify level. The amplitude of the program voltage steps down when the pass voltage steps up, to cancel out capacitive coupling to the selected storage elements from the change in the pass voltage.

Abstract: In an improved EASB programming scheme for a flash device (e.g. a NAND flash device), the number of word lines separating a selected word line (to which a program voltage is applied) and an isolation word line (to which an isolation voltage is applied) is adjusted as a function (e.g. inverse function) of distance of the selected word line from the drain side select gate to reduce program disturb due to high vertical and lateral electric fields at or near the isolation transistor when programming word lines closer to the drain side select gate. The selected and isolation word lines are preferably separated by two or more word lines to which intermediate voltage(s) are applied.

Abstract: When erasing non-volatile storage, a verification process is used between erase operations to determine whether the non-volatile storage has been successfully erased. The verification process includes separately performing verification for different subsets of the non-volatile storage elements.

Abstract: In an improved EASB programming scheme for a flash device (e.g. a NAND flash device), the number of word lines separating a selected word line (to which a program voltage is applied) and an isolation word line (to which an isolation voltage is applied) is adjusted as a function (e.g. inverse function) of distance of the selected word line from the drain side select gate to reduce program disturb due to high vertical and lateral electric fields at or near the isolation transistor when programming word lines closer to the drain side select gate. The selected and isolation word lines are preferably separated by two or more word lines to which intermediate voltage(s) are applied.

Abstract: In an improved EASB programming scheme for a flash device (e.g. a NAND flash device), the number of word lines separating a selected word line (to which a program voltage is applied) and an isolation word line (to which an isolation voltage is applied) is adjusted as a function (e.g. inverse function) of distance of the selected word line from the drain side select gate to reduce program disturb due to high vertical and lateral electric fields at or near the isolation transistor when programming word lines closer to the drain side select gate. The selected and isolation word lines are preferably separated by two or more word lines to which intermediate voltage(s) are applied.

Abstract: Non-volatile storage in which program disturb is reduced by preventing source side boosting in selected NAND strings. A self-boosting mode which includes an isolation word line is used. A channel area of an inhibited NAND string is boosted on a source side of the isolation word line before the channel is boosted on a drain side of the isolation word line. Further, storage elements near the isolation word line are kept in a conducting state during the source side boosting so that the source side channel is connected to the drain side channel. In this way, in selected NAND strings, source side boosting can not occur and thus program disturb due to source side boosting can be prevented. After the source side boosting, the source side channel is isolated from the drain side channel, and drain side boosting is performed.

Abstract: Program disturb is reduced in non-volatile storage by preventing source side boosting in selected NAND strings. A self-boosting mode which includes an isolation word line is used. A channel area of an inhibited NAND string is boosted on a source side of the isolation word line before the channel is boosted on a drain side of the isolation word line. Further, storage elements near the isolation word line are kept in a conducting state during the source side boosting so that the source side channel is connected to the drain side channel. In this way, in selected NAND strings, source side boosting can not occur and thus program disturb due to source side boosting can be prevented. After the source side boosting, the source side channel is isolated from the drain side channel, and drain side boosting is performed.

Abstract: Program disturb is reduced in non-volatile storage by preventing source side boosting in selected NAND strings. A self-boosting mode which includes an isolation word line is used. A channel area of an inhibited NAND string is boosted on a source side of the isolation word line before the channel is boosted on a drain side of the isolation word line. Further, storage elements near the isolation word line are kept in a conducting state during the source side boosting so that the source side channel is connected to the drain side channel. In this way, in selected NAND strings, source side boosting can not occur and thus program disturb due to source side boosting can be prevented. After the source side boosting, the source side channel is isolated from the drain side channel, and drain side boosting is performed.

Abstract: Non-volatile storage in which program disturb is reduced by preventing source side boosting in selected NAND strings. A self-boosting mode which includes an isolation word line is used. A channel area of an inhibited NAND string is boosted on a source side of the isolation word line before the channel is boosted on a drain side of the isolation word line. Further, storage elements near the isolation word line are kept in a conducting state during the source side boosting so that the source side channel is connected to the drain side channel. In this way, in selected NAND strings, source side boosting can not occur and thus program disturb due to source side boosting can be prevented. After the source side boosting, the source side channel is isolated from the drain side channel, and drain side boosting is performed.

Abstract: A non-volatile memory system is programmed so as to reduce or avoid program disturb. In accordance with one embodiment, multiple program inhibit schemes are employed for a single non-volatile memory system. Program inhibit schemes are selected based on the word line being programmed. Certain program inhibit schemes have been discovered to better minimize or eliminate program disturb at select word lines. In one embodiment, selecting a program inhibit scheme includes selecting a program voltage pulse ramp rate. Different ramp rates have been discovered to better minimize program disturb when applied to select word lines. In another embodiment, the temperature of a memory system is detected before or during a program operation. A program inhibit scheme can be selected based on the temperature of the system.

Abstract: In an improved EASB programming scheme for a flash device (e.g. a NAND flash device), the number of word lines separating a selected word line (to which a program voltage is applied) and an isolation word line (to which an isolation voltage is applied) is adjusted as a function (e.g. inverse function) of distance of the selected word line from the drain side select gate to reduce program disturb due to high vertical and lateral electric fields at or near the isolation transistor when programming word lines closer to the drain side select gate. The selected and isolation word lines are preferably separated by two or more word lines to which intermediate voltage(s) are applied.

Abstract: Non-volatile storage elements are programmed in a manner that reduces program disturb by using modified pass voltages. In particular, during the programming of a selected storage element associated with a selected word line, a higher pass voltage is applied to word lines associated with previously programmed non-volatile storage elements in the set than to word lines associated with unprogrammed and/or partly programmed non-volatile storage elements in the set. The pass voltage is sufficiently high to balance the channel potentials on the source and drain sides of the selected word line and/or to reduce leakage of charge between the boosted channel regions. Optionally, an isolation region is formed between the boosted channel regions by applying a reduced voltage on one or more word lines between the selected word line and the word lines that receive the higher pass voltage.

Abstract: Non-volatile storage elements are programmed in a manner that reduces program disturb by using modified pass voltages. In particular, during the programming of a selected storage element associated with a selected word line, a higher pass voltage is applied to word lines associated with previously programmed non-volatile storage elements in the set than to word lines associated with unprogrammed and/or partly programmed non-volatile storage elements in the set. The pass voltage is sufficiently high to balance the channel potentials on the source and drain sides of the selected word line and/or to reduce leakage of charge between the boosted channel regions. Optionally, an isolation region is formed between the boosted channel regions by applying a reduced voltage on one or more word lines between the selected word line and the word lines that receive the higher pass voltage.

Abstract: A non-volatile memory system is programmed so as to reduce or avoid program disturb. In accordance with one embodiment, multiple program inhibit schemes are employed for a single non-volatile memory system. Program inhibit schemes are selected based on the word line being programmed. Certain program inhibit schemes have been discovered to better minimize or eliminate program disturb at select word lines. In one embodiment, selecting a program inhibit scheme includes selecting a program voltage pulse ramp rate. Different ramp rates have been discovered to better minimize program disturb when applied to select word lines. In another embodiment, the temperature of a memory system is detected before or during a program operation. A program inhibit scheme can be selected based on the temperature of the system.