Patent application number | Description | Published |
20080247228 | NON-VOLATILE STORAGE WITH CURRENT SENSING OF NEGATIVE THRESHOLD VOLTAGES - A non-volatile storage device in which current sensing is performed for a non-volatile storage element with a negative threshold voltage. A control gate read voltage is applied to a selected word line of a non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages exceed the control gate read voltage so that a positive control gate read voltage can be used. There is no need for a negative charge pump to apply a negative word line voltage even for sensing a negative threshold voltage. A programming condition of the non-volatile storage element is determined by sensing a voltage drop which is tied to a fixed current which flows in a NAND string of the non-volatile storage element. | 10-09-2008 |
20080247229 | NON-VOLATILE STORAGE USING CURRENT SENSING WITH BIASING OF SOURCE AND P-Well - A non-volatile storage device in which current sensing is performed for a non-volatile storage element. A voltage is applied to a selected word line of the first non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages are regulated at respective positive DC levels to avoid a ground bounce, or voltage fluctuation, which would occur if the source voltage at least was regulated at a ground voltage. A programming condition of the non-volatile storage element is determined by sensing a current in a NAND string of the non-volatile storage element. The sensing can occur quickly since there is no delay in waiting for the ground bounce to settle. | 10-09-2008 |
20080247238 | METHOD FOR SENSING NEGATIVE THRESHOLD VOLTAGES IN NON-VOLATILE STORAGE USING CURRENT SENSING - Current sensing is performed in a non-volatile storage device for a selected non-volatile storage element with a negative threshold voltage. A control gate read voltage is applied to a selected word line of a non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages exceed the control gate read voltage so that a positive control gate read voltage can be used. There is no need for a negative charge pump to apply a negative word line voltage even for sensing a negative threshold voltage. A programming condition of the non-volatile storage element is determined by sensing a voltage drop which is tied to a fixed current which flows in a NAND string of the non-volatile storage element. | 10-09-2008 |
20080247239 | METHOD FOR CURRENT SENSING WITH BIASING OF SOURCE AND P-WELL IN NON-VOLATILE STORAGE - Current sensing is performed in a non-volatile storage device for a non-volatile storage element. A voltage is applied to a selected word line of the first non-volatile storage element, and source and p-well voltages are applied to a source and a p-well, respectively, associated with the non-volatile storage element. The source and p-well voltages are regulated at respective positive DC levels to avoid a ground bounce, or voltage fluctuation, which would occur if the source voltage at least was regulated at a ground voltage. A programming condition of the non-volatile storage element is determined by sensing a current in a NAND string of the non-volatile storage element. The sensing can occur quickly since there is no delay in waiting for the ground bounce to settle. | 10-09-2008 |
20080247241 | SENSING IN NON-VOLATILE STORAGE USING PULLDOWN TO REGULATED SOURCE VOLTAGE TO REMOVE SYSTEM NOISE - A pull down circuit pulls a bit line voltage to a regulated source voltage in a non-volatile storage device during a sense operation such as a verify operation which occurs during programming. The storage device may include NAND strings which have associated bit lines and sense components, and a common source line. When a selected storage element of a NAND string has been programmed to its intended state, the bit line is locked out during subsequent verify operations which occur for other NAND strings which are not yet locked out. The pull down device is coupled to each bit line and to the common source line, whose voltage is regulated at a positive DC level, to prevent coupling of system power bus (V | 10-09-2008 |
20080247253 | NON-VOLATILE STORAGE WITH TEMPERATURE COMPENSATION FOR BIT LINE DURING SENSE OPERATIONS - A non-volatile storage system in which temperature compensation of a bit line voltage is provided during a sense operation of a non-volatile storage element. A gate voltage of a transistor which couples a bit line associated with the non-volatile storage element to a sense module is temperature-compensated so that it is higher when temperature is higher to compensate for variations with temperature of the bit line voltage. The bit line voltage, in turn, varies due to variations in temperature of a threshold voltage of the non-volatile storage element. The sense module determines a programming condition of the non-volatile storage element, which may be provided in a NAND string, by sensing a voltage. The sense operation may be a read operation, verify operation, or erase-verify operation, for instance. Further, the threshold voltage of the non-volatile storage element may be positive or negative. In another aspect, a source voltage is temperature compensated. | 10-09-2008 |
20080247254 | METHOD FOR TEMPERATURE COMPENSATING BIT LINE DURING SENSE OPERATIONS IN NON-VOLATILE STORAGE - Temperature-compensation is provided during a sense operation of a non-volatile storage element. A gate voltage of a transistor which couples a bit line associated with the non-volatile storage element to a sense module is temperature-compensated so that it is higher when temperature is higher to compensate for variations with temperature of the bit line voltage. The bit line voltage, in turn, varies due to variations in temperature of a threshold voltage of the non-volatile storage element. The sense module determines a programming condition of the non-volatile storage element, which may be provided in a NAND string, by sensing a voltage. The sense operation may be a read operation, verify operation, or erase-verify operation, for instance. Further, the threshold voltage of the non-volatile storage element may be positive or negative. In another aspect, a source voltage is temperature compensated. | 10-09-2008 |
20080266963 | COMPENSATING SOURCE VOLTAGE DROP IN NON-VOLATILE STORAGE - A source line bias error caused by a voltage drop in a source line of a non-volatile memory device during a read or verify operation is addressed. In one approach, a body bias is applied to a substrate of the non-volatile memory device by coupling the substrate to a source voltage or a voltage which is a function of the source voltage. In another approach, a control gate voltage and/or drain voltage, e.g., bit line voltage, are compensated by referencing them to a voltage which is based on the source voltage instead of to ground. Various combinations of these approaches can be used as well. During other operations, such as programming, erase-verify and sensing of negative threshold voltages, the source line bias error is not present, so there is no need for a bias or compensation. A forward body bias can also be compensated. | 10-30-2008 |
20080266964 | NON-VOLATILE STORAGE WITH COMPENSATION FOR SOURCE VOLTAGE DROP - A source line bias error caused by a voltage drop in a source line of a non-volatile memory device during a read or verify operation is addressed. In one approach, a body bias is applied to a substrate of the non-volatile memory device by coupling the substrate to a source voltage or a voltage which is a function of the source voltage. In another approach, a control gate voltage and/or drain voltage, e.g., bit line voltage, are compensated by referencing them to a voltage which is based on the source voltage instead of to ground. Various combinations of these approaches can be used as well. During other operations, such as programming, erase-verify and sensing of negative threshold voltages, the source line bias error is not present, so there is no need for a bias or compensation. A forward body bias can also be compensated. | 10-30-2008 |
20090003068 | METHOD FOR SOURCE BIAS ALL BIT LINE SENSING IN NON-VOLATILE STORAGE - Bit line-to-bit line noise is discharged in a NAND string prior to sensing a programming condition of a selected non-volatile storage element in the NAND string. A source voltage is applied which boosts the voltage in conductive NAND strings. The voltage boost results in capacitive coupling of noise to neighboring NAND strings. A current pull down device is used to discharge each NAND string prior to performing sensing. After each NAND string is coupled to a discharge path for a predetermined amount of time, bit lines of the NAND string are coupled to voltage sense components for sensing the programming condition of the selected non-volatile storage elements based on a potential of the bit lines. The selected non-volatile storage elements may have a negative threshold voltage. Further, a word line associated with the selected non-volatile storage elements may be set at ground. | 01-01-2009 |
20090003069 | NON-VOLATILE STORAGE WITH SOURCE BIAS ALL BIT LINE SENSING - A NAND string in which bit line-to-bit line noise is discharged prior to sensing a programming condition of a selected non-volatile storage element in the NAND string. A source voltage is applied which boosts the voltage in conductive NAND strings. The voltage boost results in capacitive coupling of noise to neighboring NAND strings. A current pull down device is used to discharge each NAND string prior to performing sensing. After each NAND string is coupled to a discharge path for a predetermined amount of time, bit lines of the NAND string are coupled to voltage sense components for sensing the programming condition of the selected non-volatile storage elements based on a potential of the bit lines. The selected non-volatile storage elements may have a negative threshold voltage. Further, a word line associated with the selected non-volatile storage elements may be set at ground. | 01-01-2009 |
20090080265 | MULTIPLE BIT LINE VOLTAGES BASED ON DISTANCE - An array of non-volatile storage elements includes a first group of non-volatile storage elements connected to a selected word line, a second group of non-volatile storage elements connected to the selected word line, a first group of bit lines in communication with the first group of non-volatile storage elements, a second group of bit lines in communication with the second group of non-volatile storage elements, a first set of sense modules located at a first location and connected to the first group of bit lines, and a second set of sense modules located at a second location and connected to the second group of bit lines. The first set of sense modules applies a first bit line voltage based on the bit line distance between the first set of sense modules and the first group of non-volatile storage elements. The second set of sense modules applies a second bit line voltage based on the bit line distance between the second set of sense modules and the second group of non-volatile storage elements. | 03-26-2009 |
20090168540 | Low Noise Sense Amplifier Array and Method for Nonvolatile Memory - In sensing a page of nonvolatile memory cells with a corresponding group of sense modules in parallel, as each high current cell is identified, it is locked out from further sensing while others in the page continued to be sensed. The sense module involved in the locked out is then in a lockout mode and becomes inactive. A noise source from the sense module becomes significant when in the lockout mode. The noise is liable to interfere with the sensing of neighboring cells by coupling through its bit line to neighboring ones. The noise can also couple through the common source line of the page to affect the accuracy of ongoing sensing of the cells in the page. Improved sense modules and method isolate the noise from the lockout sense module from affecting the other sense modules still active in sensing memory cell in the page. | 07-02-2009 |
20090296488 | High Speed Sense Amplifier Array and Method for Nonvolatile Memory - Sensing circuits for sensing a conduction current of a memory cell among a group of non-volatile memory cells being sensed in parallel and providing the result thereof to a data bus are presented. A precharge circuit is coupled to a node for charging the node to an initial voltage. An intermediate circuit is also coupled to the node and connectable to the memory cell, whereby current from the precharge circuit can be supplied to the memory cell. The circuit also includes a comparator circuit to perform a determination the conduction current by a rate of discharge at the node; a data latch coupled to the comparator circuit to hold the result of said determination; and a transfer gate coupled to the data latch to supply a result latched therein to the data bus independently of the node. This arrangement improves sensing performance and can help to eliminate noise on the analog sensing path during sensing and reduce switching current. | 12-03-2009 |
20090323420 | MINIMIZING POWER NOISE DURING SENSING IN MEMORY DEVICE - In a sensing method, accuracy of sensing operations, such as read or verify, in a memory device is improved by avoiding fluctuations in a sense amp supply voltage which can occur when different sense amps are strobed at different times. First and second sets of sense amps perform a sensing operation on respective storage elements, such as in an all bit line configuration. The first set of sense amps is strobed at a first time point. In response, a sensed analog level is converted to digital data. The A/D conversion relies on the sense amp supply voltage being accurate. To avoid a fluctuation in the sense amp supply voltage, a bypass path allows the storage elements associated with the first set of sense amps to continue to draw power from the sense amp supply voltage. The second set of sense amps is strobed at a later, second time point. | 12-31-2009 |
20090323421 | MEMORY DEVICE WITH POWER NOISE MINIMIZATION DURING SENSING - Accuracy of sensing operations, such as read or verify, in a memory device is improved by avoiding fluctuations in a sense amp supply voltage which can occur when different sense amps are strobed at different times. First and second sets of sense amps perform a sensing operation on respective storage elements, such as in an all bit line configuration. The first set of sense amps is strobed at a first time point. In response, a sensed analog level is converted to digital data. The A/D conversion relies on the sense amp supply voltage being accurate. To avoid a fluctuation in the sense amp supply voltage, a bypass path allows the storage elements associated with the first set of sense amps to continue to draw power from the sense amp supply voltage. The second set of sense amps is strobed at a later, second time point. | 12-31-2009 |
20100008148 | Low Noise Sense Amplifier Array and Method for Nonvolatile Memory - In sensing a page of nonvolatile memory cells with a corresponding group of sense modules in parallel, as each high current cell is identified, it is locked out from further sensing while others in the page continued to be sensed. The sense module involved in the locked out is then in a lockout mode and becomes inactive. A noise source from the sense module becomes significant when in the lockout mode. The noise is liable to interfere with the sensing of neighboring cells by coupling through its bit line to neighboring ones. The noise can also couple through the common source line of the page to affect the accuracy of ongoing sensing of the cells in the page. Improved sense modules and method isolate the noise from the lockout sense module from affecting the other sense modules still active in sensing memory cell in the page. | 01-14-2010 |
20100148856 | Regulation of Recovery Rates in Charge Pumps - A method is presented of setting a frequency of a clock for a charge pump system including the clock and a charge pump. This includes setting an initial value for the frequency of the clock and, while operating the charge pump system using the clock running at the initial frequency value, determining the ramp rate of an output voltage for the charge pump during a recovery phase. The frequency of the clock is then adjusted so that the ramp rate of the output voltage for the charge pump during the recovery phase falls in a range not exceeding a predetermined maximum rate. A charge pump system is also described that includes a register having a settable value, where the charge pump clock frequency is responsive to the register value, and count and comparison circuitry is connectable to receive the pump's output voltage and the clock signal and determine from them the number of clock cycles the charge pump uses to recover from a reset value to a predetermined value. | 06-17-2010 |
20110116320 | VOLTAGE GENERATOR TO COMPENSATE SENSE AMPLIFIER TRIP POINT OVER TEMPERATURE IN NON-VOLATILE MEMORY - In a non-volatile memory system, a voltage generator provides a voltage to a gate of a voltage-setting transistor which is used in a sense circuit to set an initial voltage at a sense node. At the end of a sense period, a final voltage of the sense node is compared to a trip point, which is the threshold voltage of a voltage-sensing transistor. To account for temperature variations and manufacturing process variations, the voltage generator includes a transistor which is matched to the voltage-setting transistor, and a transistor which is matched to the voltage-sensing transistor. As a result, a voltage swing between the initial voltage and the trip point is constant, even as the initial voltage and trip point vary. In a particular implementation, the voltage generator uses a cascode current mirror circuit, and receives a reference current from a band gap voltage circuit. | 05-19-2011 |
20110205804 | High Speed Sense Amplifier Array and Method for Non-Volatile Memory - Sensing circuits for sensing a conduction current of a memory cell among a group of non-volatile memory cells being sensed in parallel and providing the result thereof to a data bus are presented. A precharge circuit is coupled to a node for charging the node to an initial voltage. An intermediate circuit is also coupled to the node and connectable to the memory cell, whereby current from the precharge circuit can be supplied to the memory cell. The circuit also includes a comparator circuit to perform a determination the conduction current by a rate of discharge at the node; a data latch coupled to the comparator circuit to hold the result of said determination; and a transfer gate coupled to the data latch to supply a result latched therein to the data bus independently of the node. This arrangement improves sensing performance and can help to eliminate noise on the analog sensing path during sensing and reduce switching current. | 08-25-2011 |
20110222345 | Non-Volatile Memory and Method With Power-Saving Read and Program-Verify Operations - A non-volatile memory device capable of reading and writing a large number of memory cells with multiple read/write circuits in parallel has features to reduce power consumption during read, and program/verify operations. A read or program verify operation includes one or more sensing cycles relative to one or more demarcation threshold voltages to determine a memory state. In one aspect, selective memory cells among the group being sensed in parallel have their conduction currents turned off when they are determined to be in a state not relevant to the current sensing cycle. In another aspect, a power-consuming period is minimized by preemptively starting any operations that would prolong the period. In a program/verify operation cells not to be programmed have their bit lines charged up in the program phase. Power is saved when a set of these bit lines avoids re-charging at every passing of a program phase. | 09-15-2011 |
20110261625 | Low Noise Sense Amplifier Array and Method for Nonvolatile Memory - In sensing a page of nonvolatile memory cells with a corresponding group of sense modules in parallel, as each high current cell is identified, it is locked out from further sensing while others in the page continued to be sensed. The sense module involved in the locked out is then in a lockout mode and becomes inactive. A noise source from the sense module becomes significant when in the lockout mode. The noise is liable to interfere with the sensing of neighboring cells by coupling through its bit line to neighboring ones. The noise can also couple through the common source line of the page to affect the accuracy of ongoing sensing of the cells in the page. Improved sense modules and method isolate the noise from the lockout sense module from affecting the other sense modules still active in sensing memory cell in the page. | 10-27-2011 |
20120243332 | Non-Volatile Memory and Method with Power-Saving Read and Program-Verify Operations - A non-volatile memory device capable of reading and writing a large number of memory cells with multiple read/write circuits in parallel has features to reduce power consumption during read, and program/verify operations. A read or program verify operation includes one or more sensing cycles relative to one or more demarcation threshold voltages to determine a memory state. In one aspect, selective memory cells among the group being sensed in parallel have their conduction currents turned off when they are determined to be in a state not relevant to the current sensing cycle. In another aspect, a power-consuming period is minimized by preemptively starting any operations that would prolong the period. In a program/verify operation cells not to be programmed have their bit lines charged up in the program phase. Power is saved when a set of these bit lines avoids re-charging at every passing of a program phase. | 09-27-2012 |
20130070530 | HIGH ENDURANCE NON-VOLATILE STORAGE - A non-volatile storage system is disclosed that includes non-volatile memory cells designed for high endurance and lower retention than other non-volatile memory cells. | 03-21-2013 |
20130107628 | Selective Word Line Erase In 3D Non-Volatile Memory | 05-02-2013 |
20130176776 | Charge Cycling By Equalizing and Regulating the Source, Well, and Bit Line Levels During Write Operations for NAND Flash Memory: Program to Verify Transition - In non-volatile memory devices, a write typically consists of an alternating set of pulse and verify operations. At the end of a pulse, the device must be biased properly for an accurate verify, after which the device is re-biased for the next pulse. The intervals between the pulse and verify phases are considered. For the interval after a pulse, but before establishing the verify conditions, the source, bit line, and, optionally, the well levels can be equalized and then regulated at a desired DC level. After a verify phase, but before applying the biasing the memory for the next pulse, the source and bit line levels can be equalized to a DC level. | 07-11-2013 |
20130176777 | Charge Cycling By Equalizing and Regulating the Source, Well, and Bit Line Levels During Write Operations for NAND Flash Memory: Verify to Program Transition - In non-volatile memory devices, a write typically consists of an alternating set of pulse and verify operations. At the end of a pulse, the device must be biased properly for an accurate verify, after which the device is re-biased for the next pulse. The intervals between the pulse and verify phases are considered. For the interval after a pulse, but before establishing the verify conditions, the source, bit line, and, optionally, the well levels can be equalized and then regulated at a desired DC level. After a verify phase, but before applying the biasing the memory for the next pulse, the source and bit line levels can be equalized to a DC level. | 07-11-2013 |
20130176790 | Charge Cycling By Equalizing the Source and Bit Line Levels Between Pulses During No-Verify Write Operations for NAND Flash Memory - In non-volatile memory devices, a write typically consists of an alternating set of pulse and verify operations. At the end of a pulse, the device must be biased properly for an accurate verify, after which the device is re-biased for the next pulse. In some cases a non-volatile memory is programmed by an alternating set of pulses, but, for at least some pulses without any intervening verify operations. After a one pulse, but before biasing the memory for the next pulse without an intervening very, the source and bit line levels can be left to float. | 07-11-2013 |
20130223155 | TEMPERATURE BASED COMPENSATION DURING VERIFY OPERATIONS FOR NON-VOLATILE STORAGE - A non-volatile storage system that performs programming and reading processes. The programming process includes coarse/fine programming and verify operations. Programming is verified by testing for two different threshold voltage levels while applying the same voltage level to the control gate of a memory cell by testing for current levels through the memory cells and adjusting the current levels tested for based on current temperature such that the difference between the two effective tested threshold voltage levels remains constant over temperature variation. | 08-29-2013 |
20130258772 | Non-Volatile Memory and Method Having a Memory Array with a High-Speed, Short Bit-Line Portion - A non-volatile memory array is partitioned along the column direction into first and second portions. The first portion has SLC memory cells and the second portion has MLC memory cells. The first portion acts as a fast cache memory for the second portion. The read/write operations of the first portion are further enhanced by coupling to a set of read/write circuits immediately adjacent to the first portion, while the column of each bit line is switchably cut off at the junction between the first and second portions. In this way, the RC constant of the cut off bit line is at a minimum, which translates to faster precharge of the bit line via the read/write circuits. When the second portion is operating, its access to the set of read/write circuits is accomplished by not cutting off each bit line at the junction between the first and second portions. | 10-03-2013 |
20140003153 | Compact High Speed Sense Amplifier for Non-Volatile Memory | 01-02-2014 |
20140003157 | Compact High Speed Sense Amplifier for Non-Volatile Memory and Hybrid Lockout | 01-02-2014 |
20140003176 | Compact High Speed Sense Amplifier for Non-Volatile Memory with Reduced layout Area and Power Consumption | 01-02-2014 |
20140022841 | Memory System with Unverified Program Step - In a programming operation that includes repeated bitscan, program, and verify steps, the bitscan steps may be hidden by performing bitscan in parallel with program preparation and program steps. The effect of a program step may be predicted from previous observation so that when a bitscan indicates that the memory cells are close to being programmed, a last programming step may be completed without subsequent verification or bitscan steps. | 01-23-2014 |
20140036601 | TEMPERATURE BASED COMPENSATION DURING VERIFY OPERATIONS FOR NON-VOLATILE STORAGE - A non-volatile storage system that performs programming and reading processes. The programming process includes coarse/fine programming and verify operations. Programming is verified by testing for two different threshold voltage levels while applying the same voltage level to the control gate of a memory cell by testing for current levels through the memory cells and adjusting the current levels tested for based on current temperature such that the difference between the two effective tested threshold voltage levels remains constant over temperature variation. | 02-06-2014 |
20140133229 | BIT LINE RESISTANCE COMPENSATION - Methods for compensating for variations in bit line resistance during sensing of memory cells are described. The variations in bit line resistance may occur die-to-die or plane-to-plane on the same die. In some embodiments, for each die or memory plane on a die, a plurality of bit line read voltages associated with a plurality of zones may be determined based on sensing criteria. The sensing criteria may comprise a number of fail bits. Each zone of the plurality of zones may be associated with a memory array region within a die or memory plane. Prior to performing a read or verify operation on a group of memory cells, a bit line read voltage used during sensing of the group of memory cells may be determined based on the plurality of bit line read voltages and a zone associated with the group of memory cells. | 05-15-2014 |
20140133230 | BIT LINE RESISTANCE COMPENSATION - Methods for compensating for variations in bit line resistance during sensing of memory cells are described. The variations in bit line resistance may occur die-to-die or plane-to-plane on the same die. In some embodiments, for each die or memory plane on a die, a plurality of bit line read voltages associated with a plurality of zones may be determined based on sensing criteria such as a number of fail bits. Each zone of the plurality of zones may be associated with a memory array region within a memory plane. Within each zone, different bit line read voltages may be applied to different bit line groupings in order to compensate for systematic variations in bit line resistance between neighboring bit lines due to the use of multiple patterning lithography techniques such as spacer-based double patterning. | 05-15-2014 |
20140133231 | BIT LINE RESISTANCE COMPENSATION - Methods for compensating for variations in bit line resistance in non-volatile memories are described. In some embodiments, use of multiple patterning lithography for forming bit lines may lead to systematic variations in bit line resistance between groups of bit lines within a memory array. For example, in some cases, every fourth bit line of four neighboring (or adjacent) bit lines may be formed differently than the other three bit lines within a group of four neighboring bit lines. In one embodiment, bit line segment swapping may be used between blocks within a memory array in order to mitigate variations in bit line resistance. In another embodiment, each group of adjacent bit line segments may be offset (or staggered) per block such that the local routing necessary to connect bit line segments into bit lines may be simplified. | 05-15-2014 |
20140211568 | BIT LINE CURRENT TRIP POINT MODULATION FOR READING NONVOLATILE STORAGE ELEMENTS - Upon selecting non-volatile storage elements to be sensed, the system obtains information about the position of these non-volatile storage elements, determines sensing parameters based at least in part on this information, pre-charges a charge storage device and, while maintaining the voltage level of the bit lines of these memory cells at a constant value, applies a reference signal to these non-volatile storage elements for a certain duration of time, afterwards determining whether, for the certain duration of time, the current conducted by these non-volatile storage elements exceeds a predetermined value. | 07-31-2014 |
20140269083 | BIT LINE CURRENT TRIP POINT MODULATION FOR READING NONVOLATILE STORAGE ELEMENTS - Upon selecting non-volatile storage elements to be sensed, the system obtains information about the position of these non-volatile storage elements, determines sensing parameters based at least in part on this information, pre-charges a charge storage device and, while maintaining the voltage level of the bit lines of these memory cells at a constant value, applies a reference signal to these non-volatile storage elements for a certain duration of time, afterwards determining whether, for the certain duration of time, the current conducted by these non-volatile storage elements exceeds a predetermined value. | 09-18-2014 |
20140269100 | SHARED BIT LINE STRING ARCHITECTURE - Methods for programming and reading memory cells using a shared bit line string architecture are described. In some embodiments, memory cells and select devices may correspond with transistors including a charge storage layer. In some cases, the charge storage layer may be conductive (e.g., a polysilicon layer as used in a floating gate device) or non-conductive (e.g., a silicon nitride layer as used in a SONOS device). In some embodiments, selection of a memory cell in a first string of a pair of strings may include setting an SEO transistor into a conducting state and setting an SGD line controlling drain-side select transistors to a voltage that is greater than a first threshold voltage associated with a first drain-side select transistor of the first string and less than a second threshold voltage associated with a second drain-side select transistor of a second string of the pair of strings. | 09-18-2014 |
20140355344 | Adaptive Operation of Three Dimensional Memory - When data from a portion of a three dimensional NAND memory array is determined to be uncorrectable by Error Correction Code (ECC), a determination is made as to whether data is uncorrectable by ECC throughout some unit that is larger than the portion. If modified read conditions provide ECC correctable data, the modified read conditions are recorded for subsequent reads of the larger unit. | 12-04-2014 |
20140355345 | Adaptive Operation of Three Dimensional Memory - When data from a portion of a three dimensional NAND memory array is determined to be uncorrectable by Error Correction Code (ECC), a determination is made as to whether data is uncorrectable by ECC throughout some unit that is larger than the portion. If modified read conditions provide ECC correctable data, the modified read conditions are recorded for subsequent reads of the larger unit. | 12-04-2014 |
20140359398 | Selection of Data for Redundancy Calculation in Three Dimensional Nonvolatile Memory - Portions of data stored in a three dimensional memory array are selected based on their locations for calculation of redundancy data. Locations are selected so that no two portions in a set of portions for a given calculation are likely to become uncorrectable at the same time. Selected portions may be separated by at least one word line and separated by at least one string in a block. | 12-04-2014 |
20140359400 | Selection of Data for Redundancy Calculation in Three Dimensional Nonvolatile Memory - Portions of data stored in a three dimensional memory array are selected based on their locations for calculation of redundancy data. Locations are selected so that no two portions in a set of portions for a given calculation are likely to become uncorrectable at the same time. Selected portions may be separated by at least one word line and separated by at least one string in a block. | 12-04-2014 |
20150063033 | Selective Word Line Erase In 3D Non-Volatile Memory - An erase process for a 3D stacked memory device allows a portion of a block of memory cells to be erased. In one approach, in a U-shaped NAND string configuration, memory cells in the drain- or source-side columns are erased. In another approach, such as in a U-shaped or a straight NAND string configuration, memory cells in a portion of a column of memory cells are erased, and a dummy memory cell is provided between the erased and non-erased memory cells. A dummy memory cell can be on either side (e.g., above and below) of an erase memory cell, or on either side of a non-erased memory cell. A dummy memory cell is ineligible to store user data, but prevents a downshift in the threshold voltage of an erased memory cell from changing the threshold voltage of a non-erased memory cell, due to capacitive coupling. | 03-05-2015 |