摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A non-volatile semiconductor memory system (or other type of memory system) is programmed in a manner that avoids program disturb. In one embodiment that includes a flash memory system using a NAND architecture, program disturb is avoided by increasing the channel potential of the source side of the NAND string during the programming process. One exemplar implementation includes applying a voltage (e.g. Vdd) to the source contact and turning on the source side select transistor for the NAND sting corresponding to the cell being inhibited. Another implementation includes applying a pre-charging voltage to the unselected word lines of the NAND string corresponding to the cell being inhibited prior to applying the program voltage.
摘要:
A flash memory device of the multi-level cell (MLC) type, in which control gate voltages in read and programming operations and a bandgap reference voltage source are trimmable from external terminals, is disclosed. In a special test mode, control gate voltages can be applied to a selected programmed memory cell so that the threshold voltage of the cell can be sensed. A digital-to-analog converter (DAC) use for programming and a second read/verify DAC apply varying analog voltages and are sequentially used to verify the programming of an associated set of memory cells in this special test mode, with the DAC input values that provide the closest result selected for use in normal operation. These DAC's are dependent on the value of a reference source that my also be trimmed.
摘要:
A flash memory device of the multi-level cell (MLC) type, in which control gate voltages in read and programming operations and a bandgap reference voltage source are trimmable from external terminals, is disclosed. In a special test mode, control gate voltages can be applied to a selected programmed memory cell so that the threshold voltage of the cell can be sensed. A digital-to-analog converter (DAC) use for programming and a second read/verify DAC apply varying analog voltages and are sequentially used to verify the programming of an associated set of memory cells in this special test mode, with the DAC input values that provide the closest result selected for use in normal operation. These DAC's are dependent on the value of a reference source that my also be trimmed.
摘要:
A flash memory device of the multi-level cell (MLC) type, in which control gate voltages in read and programming operations and a bandgap reference voltage source are trimmable from external terminals, is disclosed. In a special test mode, control gate voltages can be applied to a selected programmed memory cell so that the threshold voltage of the cell can be sensed. A digital-to-analog converter (DAC) use for programming and a second read/verify DAC apply varying analog voltages and are sequentially used to verify the programming of an associated set of memory cells in this special test mode, with the DAC input values that provide the closest result selected for use in normal operation. These DAC's are dependent on the value of a reference source that my also be trimmed.
摘要:
Systems and methods in accordance with various embodiments can provide for comprehensive erase verification and defect detection in non-volatile semiconductor memory. In one embodiment, the results of erasing a group of storage elements is verified using a plurality of test conditions to better detect defective and/or insufficiently erased storage elements of the group. For example, the results of erasing a NAND string can be verified by testing charging of the string in a plurality of directions with the storage elements biased to turn on if in an erased state. If a string of storage elements passes a first test process or operation but fails a second test process or operation, the string can be determined to have failed the erase process and possibly be defective. By testing charging or conduction of the string in a plurality of directions, defects in any transistors of the string that are masked under one set of conditions may be exposed under a second set of bias conditions. For example, a string may pass an erase verification operation but then be read as including one or more programmed storage elements. Such a string can be defective and mapped out of the memory device.
摘要:
Systems and methods in accordance with various embodiments can provide for comprehensive erase verification and defect detection in non-volatile semiconductor memory. In one embodiment, the results of erasing a group of storage elements is verified using a plurality of test conditions to better detect defective and/or insufficiently erased storage elements of the group. For example, the results of erasing a NAND string can be verified by testing charging of the string in a plurality of directions with the storage elements biased to turn on if in an erased state. If a string of storage elements passes a first test process or operation but fails a second test process or operation, the string can be determined to have failed the erase process and possibly be defective. By testing charging or conduction of the string in a plurality of directions, defects in any transistors of the string that are masked under one set of conditions may be exposed under a second set of bias conditions. For example, a string may pass an erase verification operation but then be read as including one or more programmed storage elements. Such a string can be defective and mapped out of the memory device.