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 a constant pulse width and increasing magnitudes until a maximum voltage is reached. At that point, the magnitude of the programming pulses stops increasing and the programming pulses are applied in a manner to provide varying time duration of the programming signal between verification operations. In one embodiment, for example, after the pulses reach the maximum magnitude the pulse widths are increased. In another embodiment, after the pulses reach the maximum magnitude multiple program pulses are applied between verification operations.
Abstract:
A system is disclosed for reducing or removing a form of read disturb in a non-volatile storage device. One embodiment seeks to prevent read disturb by eliminating or minimizing boosting of the channel of the memory elements. For example, one implementation prevents or reduces boosting of the source side of the NAND string channel during a read process. Because the source side of the NAND string channel is not boosted, at least one form of read disturb is minimized or does not occur.
Abstract:
Maximized multi-state compaction and more tolerance in memory state behavior is achieved through a flexible, self-consistent and self-adapting mode of detection, covering a wide dynamic range. For high density multi-state encoding, this approach borders on full analog treatment, dictating analog techniques including A to D type conversion to reconstruct and process the data. In accordance with the teachings of this invention, the memory array is read with high fidelity, not to provide actual final digital data, but rather to provide raw data accurately reflecting the analog storage state, which information is sent to a memory controller for analysis and detection of the actual final digital data.
Abstract:
A “smart verify” technique, whereby multi-state memories are programmed using a verify-results-based dynamic adjustment of the multi-states verify range for sequential-state-based verify implementations, is presented. This technique can increase multi-state write speed while maintaining reliable operation within sequentially verified, multi-state memory implementations by providing “intelligent” means to minimize the number of sequential verify operations for each program/verify/lockout step of the write sequence. At the beginning of a program/verify cycle sequence only the lowest state or states are checked during the verify phase. As lower states are reached, additional higher states are added to the verify sequence and lower states can be removed.
Abstract:
A system for reducing or removing a form of read disturb in a non-volatile storage device. One embodiment seeks to prevent read disturb by eliminating or minimizing boosting of the channel of the memory elements. For example, one implementation prevents or reduces boosting of the source side of the NAND string channel during a read process. Because the source side of the NAND string channel is not boosted, at least one form of read disturb is minimized or does not occur.
Abstract:
For a non-volatile memory system, compressing the erase threshold voltage distribution into the lowest threshold voltage state will decrease the valid data threshold voltage window. Decreasing the valid data threshold voltage window reduces the floating gate to floating gate coupling effect. The compression can be performed as part of the erase process or part of the programming operation.
Abstract:
A non-volatile memory device is programmed by first performing a coarse programming process and subsequently performing a fine programming process. The coarse/fine programming methodology is enhanced by using an efficient verification scheme that allows some non-volatile memory cells to be verified for the coarse programming process while other non-volatile memory cells are verified for the fine programming process. The fine programming process can be accomplished using current sinking, charge packet metering or other suitable means.
Abstract:
A non-volatile memory device is programmed by first performing a coarse programming process and subsequently performing a fine programming process. The coarse/fine programming methodology is enhanced by using an efficient verification scheme that allows some non-volatile memory cells to be verified for the coarse programming process while other non-volatile memory cells are verified for the fine programming process. The fine programming process can be accomplished using current sinking, charge packet metering or other suitable means.
Abstract:
Maximized multi-state compaction and more tolerance in memory state behavior is achieved through a flexible, self-consistent and- self-adapting mode of detection, covering a wide dynamic range. For high density multi-state encoding, this approach borders on full analog treatment, dictating analog techniques including A to D type conversion to reconstruct and process the data. In accordance with the teachings of this invention, the memory array is read with high fidelity, not to provide actual final digital data, but rather to provide raw data accurately reflecting the analog storage state, which information is sent to a memory controller for analysis and detection of the actual final digital data.
Abstract:
A non-volatile memory system having an array of memory cells with at least one storage element each is operated with a plurality of storage level ranges per storage element. A flash electrically erasable and programmable read only memory (EEPROM) is an example, wherein the storage elements are electrically floating gates. The memory is operated to minimize the effect of charge coupled between adjacent floating gates, by programming some cells a second time after adjacent cells have been programmed. The second programming step also compacts a distribution of charge levels within at least some of the programming states. This increases the separation between states and/or allows more states to be included within a given storage window. An implementation that is described is for a NAND type of flash EEPROM.