Patent application number | Description | Published |
20090296475 | VERIFICATION PROCESS FOR NON-VOLATILE STORAGE - 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. | 12-03-2009 |
20100149881 | ADAPTIVE ERASE AND SOFT PROGRAMMING FOR MEMORY - An erase sequence of a non-volatile storage device includes an erase operation followed by a soft programming operation. The erase operation applies one or more erase pulses to the storage elements, e.g., via a substrate, until an erase verify level is satisfied. The number of erase pulses is tracked and recorded as an indicia of the number of programming-erase cycles which the storage device has experienced. The soft programming operation applies soft programming pulses to the storage elements until a soft programming verify level is satisfied. Based on the number of erase pulses, the soft programming operation time is shortened by skipping verify operations for a specific number of initial soft programming pulses which is a function of the number of erase pulses. Also, a characteristic of the soft programming operation can be optimized, such as starting amplitude, step size or pulse duration. | 06-17-2010 |
20110019483 | ADAPTIVE ERASE AND SOFT PROGRAMMING FOR MEMORY - An erase sequence of a non-volatile storage device includes an erase operation followed by a soft programming operation. The erase operation applies one or more erase pulses to the storage elements, e.g., via a substrate, until an erase verify level is satisfied. The number of erase pulses is tracked and recorded as an indicia of the number of programming-erase cycles which the storage device has experienced. The soft programming operation applies soft programming pulses to the storage elements until a soft programming verify level is satisfied. Based on the number of erase pulses, the soft programming operation time is shortened by skipping verify operations for a specific number of initial soft programming pulses which is a function of the number of erase pulses. Also, a characteristic of the soft programming operation can be optimized, such as starting amplitude, step size or pulse duration. | 01-27-2011 |
20110235423 | VERIFICATION PROCESS FOR NON-VOLATILE STORAGE - 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. | 09-29-2011 |
20120300550 | Ramping Pass Voltage To Enhance Channel Boost In Memory Device, With Optional Temperature Compensation - In a non-volatile storage system, one or more substrate channel regions for an unselected NAND string are boosted during programming to inhibit program disturb. A voltage applied to one or more unselected word lines associated with at least a first channel region is increased during a program pulse time period in which a program pulse is applied to a selected word line. The increase can be gradual, in the form of a ramp, or step-wise. The boosting level of the first channel region can be maintained. The increase in the voltage applied to the one or more unselected word lines can vary with temperature as well. Before the program pulse time period, the voltage applied to the one or more unselected word lines can be ramped up at a faster rate for a second, adjacent channel region than for the first channel region, to help isolate the channel regions. | 11-29-2012 |
20130250689 | SELECTED WORD LINE DEPENDENT SELECT GATE DIFFUSION REGION VOLTAGE DURING PROGRAMMING - Methods and devices for operating non-volatile storage are disclosed. One or more programming conditions depend on the location of the word line that is selected for programming. Applying a selected word line dependent program condition may reduce or eliminate program disturb. The voltage applied to a common source line may depend on the location of the word line that is selected for programming. This may prevent or reduce punch-through conduction, which may prevent or reduce program disturb. The voltage applied to bit lines of unselected NAND strings may depend on the location of the word line that is selected for programming. This may prevent or reduce punch-through conduction. | 09-26-2013 |
20130314987 | Ramping Pass Voltage To Enhance Channel Boost In Memory Device - In a non-volatile storage system, first and second substrate channel regions for an unselected NAND string are boosted during programming to inhibit program disturb. The first and second substrate channel regions are created on either side of an isolation word line. During a program pulse time period in which a program pulse is applied to a selected word line, a voltage applied to an unselected word line which extends directly over the second channel region is stepped up to a respective pre-program pulse voltage, at a faster rate at which a voltage applied to an unselected word line which extends directly over the first channel region is stepped up to a respective pre-program pulse voltage. This helps improve the isolation between the channel regions. | 11-28-2013 |
20140247663 | NON-VOLATILE STORAGE WITH PROCESS THAT REDUCES READ DISTURB ON END WORDLINES - A system for reducing read disturb on edge word lines in non-volatile storage is disclosed. In one embodiment, the memory cells on edge word lines are programmed using a series of pulses that have an initial magnitude and step size between pulses that are lower than for memory cells on word lines that are not edge word lines. Additionally, when reading memory cells on word lines that are not edge word lines, the edge word lines receive a lower pass voltage than the default pass voltage applied to other unselected word lines. In another embodiment, the system applies a higher than normal bias on a neighboring word lines when reading memory cells on an edge word line. | 09-04-2014 |
20140247666 | DYNAMIC ERASE DEPTH FOR IMPROVED ENDURANCE OF NON-VOLATILE MEMORY - Improving endurance for non-volatile memory by dynamic erase depth is disclosed. A group of memory cells are erased. Then, at least some of the erased memory cells are programmed. Programming the memory cells typically impacts the erase threshold distribution of those memory cells that were intended to stay erased. The erase depth of the next erase can be adjusted based on how the program operation affects the erase threshold distribution. As one example, the upper tail of the erase distribution is measured after programming. The higher the upper tail, the shallower the next erase, in one embodiment. This helps to improve endurance. In one embodiment, the erase depth is adjusted by determining a suitable erase verify level. Rather than (or in addition to) adjusting the erase verify level, the number of erase pulses that are performed after erase verify passes can be adjusted to adjust the erase depth. | 09-04-2014 |
20140247667 | PARTITIONED ERASE AND ERASE VERIFICATION IN NON-VOLATILE MEMORY - A set of memory cells can be erased by individually erasing portions of the set in order to normalize the erase behavior of each memory cell and provide more consistent erase rates. An erase voltage pulse can be applied to the set of memory cells with a first group of cells biased for erase and a second group biased to inhibit erase. The erase depth is made shallower as the device is cycled more. | 09-04-2014 |