Patent application number | Description | Published |
20080198660 | MULTIPLE PASS WRITE SEQUENCE FOR NON-VOLATILE STORAGE - A set of non-volatile storage elements are erased to an erased threshold voltage distribution. A multi-pass programming process is performed that programs the set of non-volatile storage elements from the erased threshold voltage distribution to a set valid data threshold voltage distributions. Each programming pass has one or more starting threshold voltage distributions and programs non-volatile storage elements to at least two ending threshold voltage distributions. | 08-21-2008 |
20080198661 | NON-VOLATILE STORAGE APPARATUS WITH VARIABLE INITIAL PROGRAM VOLTAGE MAGNITUDE - Multiple programming processes are performed for a plurality of non-volatile storage elements. Each of the programming process operates to program at least a subset of said non-volatile storage elements to a set of target conditions using program pulses. In one embodiment, a first programming pass includes soft programming and additional programming passes include the programming of data. In another embodiment, all of the programming process include programming data. For at least a subset of said programming processes, a program pulse associated with achieving a particular result for a respective programming process is identified. The identified program pulse is used to adjust programming for a subsequent programming process. | 08-21-2008 |
20080198662 | DYNAMIC VERIFY BASED ON THRESHOLD VOLTAGE DISTRIBUTION - After erasing a plurality of non-volatile storage elements, a soft programming process is performed to tighten the erase threshold distribution for the non-volatile storage elements. During the soft programming process, the system identifies the number of programming pulses needed for a first set of the non-volatile storage elements to complete the soft programming and the number of programming pulses needed for the all but a last set of non-volatile storage elements to complete soft programming. These two numbers are used to characterize the threshold distribution of the non-volatile storage elements. This characterization of the threshold distribution and the program pulse step size are used to limit the number of verify pulses used during subsequent programming. | 08-21-2008 |
20080198664 | NON-VOLATILE STORAGE APPARATUS WITH MULTIPLE PASS WRITE SEQUENCE - A set of non-volatile storage elements are erased to an erased threshold voltage distribution. A multi-pass programming process is performed that programs the set of non-volatile storage elements from the erased threshold voltage distribution to a set valid data threshold voltage distributions. Each programming pass has one or more starting threshold voltage distributions and programs non-volatile storage elements to at least two ending threshold voltage distributions. | 08-21-2008 |
20080198665 | VARIABLE INITIAL PROGRAM VOLTAGE MAGNITUDE FOR NON-VOLATILE STORAGE - Multiple programming processes are performed for a plurality of non-volatile storage elements. Each of the programming process operates to program at least a subset of said non-volatile storage elements to a set of target conditions using program pulses. In one embodiment, a first programming pass includes soft programming and additional programming passes include the programming of data. In another embodiment, all of the programming process include programming data. For at least a subset of said programming processes, a program pulse associated with achieving a particular result for a respective programming process is identified. The identified program pulse is used to adjust programming for a subsequent programming process. | 08-21-2008 |
20080237602 | THREE DIMENSIONAL NAND MEMORY - A monolithic, three dimensional NAND string includes a first memory cell located over a second memory cell. A semiconductor active region of the first memory cell is formed epitaxially on a semiconductor active region of the second memory cell, such that a defined boundary exists between the semiconductor active region of the first memory cell and the semiconductor active region of the second memory cell. | 10-02-2008 |
20080237698 | METHOD OF MAKING THREE DIMENSIONAL NAND MEMORY - A monolithic, three dimensional NAND string includes a first memory cell located over a second memory cell. A semiconductor active region of the first memory cell is a first pillar having a square or rectangular cross section when viewed from above, the first pillar being a first conductivity type semiconductor region located between second conductivity type semiconductor regions. A semiconductor active region of the second memory cell is a second pillar having a square or rectangular cross section when viewed from above, the second pillar located under the first pillar, the second pillar being a first conductivity type semiconductor region located between second conductivity type semiconductor regions. One second conductivity type semiconductor region in the first pillar contacts one second conductivity type semiconductor region in the second pillar. | 10-02-2008 |
20080239813 | Method of Compensating Variations along a Word Line in a Non-Volatile Memory - Variation in programming efficacy due to variation in time constants along a word line that spans across a memory plane is compensated by adjusting the bit line voltages across the plane to modify the programming rates. In this way, the variation in programming efficacy is substantially reduced during programming of a group of memory cells coupled to the word line. This will allow uniform optimization of programming across the group of memory cells and reduce the number of programming pulses required to program the group of memory cells, thereby improving performance. In one embodiment, during programming, the bit lines in a first half of the memory plane closer to a source of word line voltage is set to a first voltage by a first voltage shifter and the bit lines in a second half of the memory plane further from the source of word line voltage is set to a second voltage by a second voltage shifter. | 10-02-2008 |
20080239818 | THREE DIMENSIONAL NAND MEMORY - A monolithic, three dimensional NAND string includes a first memory cell located over a second memory cell, a select transistor, a first word line of the first memory cell, a second word line of the second memory cell, a bit line, a source line, and a select gate line of the select transistor. The first and the second word lines are not parallel to the bit line, and the first and the second word lines extend parallel to at least one of the source line and the select gate line. | 10-02-2008 |
20080239821 | NAND MEMORY WITH SIDE-TUNNELING - A string of nonvolatile memory cells are formed with control gates extending between floating gates, control gates and floating gates separated by tunnel dielectric layers. Electron tunneling between control gates and floating gates is used for programming. A process for forming a memory array forms odd numbered floating gates from a first layer and even numbered floating gates from a second layer. | 10-02-2008 |
20080239824 | Non-Volatile Memory with Compensation for Variations Along a Word Line - Variation in programming efficacy due to variation in time constants along a word line that spans across a memory plane is compensated by adjusting the bit line voltages across the plane to modify the programming rates. In this way, the variation in programming efficacy is substantially reduced during programming of a group of memory cells coupled to the word line. This will allow uniform optimization of programming across the group of memory cells and reduce the number of programming pulses required to program the group of memory cells, thereby improving performance. In one embodiment, during programming, the bit lines in a first half of the memory plane closer to a source of word line voltage is set to a first voltage and the bit lines in a second half of the memory plane further from the source of word line voltage is set to a second voltage. | 10-02-2008 |
20080239827 | METHODS OF FORMING AND OPERATING NAND MEMORY WITH SIDE-TUNNELING - A string of nonvolatile memory cells are formed with control gates extending between floating gates, control gates and floating gates separated by tunnel dielectric layers. Electron tunneling between control gates and floating gates is used for programming. A process for forming a memory array forms odd numbered floating gates from a first layer and even numbered floating gates from a second layer. | 10-02-2008 |
20080242008 | METHOD OF MAKING THREE DIMENSIONAL NAND MEMORY - A method of making a monolithic, three dimensional NAND string, includes forming a select transistor, forming a first memory cell over a second memory cell, forming a first word line for the first memory cell, forming a second word line for the second memory cell, forming a bit line, forming a source line, and forming a select gate line for the select transistor. The first and the second word lines are not parallel to the bit line, and the first and the second word lines extend parallel to at least one of the source line and the select gate line. | 10-02-2008 |
20080242028 | METHOD OF MAKING THREE DIMENSIONAL NAND MEMORY - A method of making a monolithic, three dimensional NAND string including a first memory cell located over a second memory cell, includes growing a semiconductor active region of second memory cell, and epitaxially growing a semiconductor active region of the first memory cell on the semiconductor active region of the second memory cell in a different growth step from the step of growing the semiconductor active region of second memory cell. | 10-02-2008 |
20080242034 | METHOD OF MAKING THREE DIMENSIONAL NAND MEMORY - A method of making a monolithic, three dimensional NAND string, includes forming a semiconductor active region of a first memory cell over a semiconductor active region of a second memory cell. The semiconductor active region of the first memory cell is a first pillar having a square or rectangular cross section when viewed from above, the first pillar being a first conductivity type semiconductor region located between second conductivity type semiconductor regions. The semiconductor active region of the second memory cell is a second pillar having a square or rectangular cross section when viewed from above, the second pillar located under the first pillar, the second pillar being a first conductivity type semiconductor region located between second conductivity type semiconductor regions. One second conductivity type semiconductor region in the first pillar contacts one second conductivity type semiconductor region in the second pillar. | 10-02-2008 |
20080244162 | METHOD FOR READING NON-VOLATILE STORAGE USING PRE-CONDITIONING WAVEFORMS AND MODIFIED RELIABILITY METRICS - Data stored in non-volatile storage is read using sense operations and associated pre-conditioning waveforms. The pre-conditioning waveform provides a short term history for a non-volatile element which is analogous to the conditions experienced during programming when a programming pulse is applied prior to a verify operation. The pre-conditioning waveform can cause electrons to enter and exit trap sites, for instance, so that the accuracy of a probabilistic decoding process is improved. In one approach, multiple read operations are performed, some with pre-conditioning waveforms and some without. Pre-conditioning waveforms with different characteristics, such as amplitude, shape, duration and time before the associated read pulse, can also be used. For probabilistic decoding, initial reliability metrics can be developed based on multiple reads. Tables which store the reliability metrics can then be prepared for use in subsequent decoding. | 10-02-2008 |
20080244338 | Soft bit data transmission for error correction control in non-volatile memory - Data stored in non-volatile storage is decoded using iterative probabilistic decoding. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding sensed states of a set of non-volatile storage element. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. Soft data bits are read from the memory if the decoding fails to converge. Initial reliability metric values are provided after receiving the hard read results and at each phase of the soft bit operation(s). In one embodiment, a second soft bit is read from the memory using multiple subsets of soft bit compare levels. While reading at the second subset of compare levels, decoding can be performed based on the first subset data. | 10-02-2008 |
20080244360 | Non-Volatile Memory with Soft Bit Data Transmission for Error Correction Control - Data stored in non-volatile storage is decoded using iterative probabilistic decoding. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding sensed states of a set of non-volatile storage element. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. Soft data bits are read from the memory if the decoding fails to converge. Initial reliability metric values are provided after receiving the hard read results and at each phase of the soft bit operation(s). In one embodiment, a second soft bit is read from the memory using multiple subsets of soft bit compare levels. While reading at the second subset of compare levels, decoding can be performed based on the first subset data. | 10-02-2008 |
20080244367 | NON-VOLATILE MEMORY WITH GUIDED SIMULATED ANNEALING ERROR CORRECTION CONTROL - Data stored in non-volatile storage is decoded using iterative probabilistic decoding. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding sensed states of a set of non-volatile storage elements. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. Simulated annealing using an adjustable temperature parameter based on a level of error in the data read from the system can be performed to assist the iterative decoding process. The simulated annealing can introduce randomness, as noise for example, into the metric based decoding process. Moreover, knowledge of the device characteristics can be used to guide the simulated annealing process rather than introducing absolute randomness. The introduction of a degree of randomness adds flexibility during the iterative decoding that permits possible faster convergence times and convergence in situations where data may otherwise be uncorrectable. | 10-02-2008 |
20080244368 | Guided Simulated Annealing in Non-Volatile Memory Error Correction Control - Data stored in non-volatile storage is decoded using iterative probabilistic decoding. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding sensed states of a set of non-volatile storage elements. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. Simulated annealing using an adjustable temperature parameter based on a level of error in the data read from the system can be performed to assist the iterative decoding process. The simulated annealing can introduce randomness, as noise for example, into the metric based decoding process. Moreover, knowledge of the device characteristics can be used to guide the simulated annealing process rather than introducing absolute randomness. The introduction of a degree of randomness adds flexibility during the iterative decoding that permits possible faster convergence times and convergence in situations where data may otherwise be uncorrectable. | 10-02-2008 |
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 |
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 |
20080250300 | METHOD FOR DECODING DATA IN NON-VOLATILE STORAGE USING RELIABILITY METRICS BASED ON MULTIPLE READS - Data stored in non-volatile storage is decoded using iterative probabilistic decoding and multiple read operations to achieve greater reliability. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding read data of a set of non-volatile storage element. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. If convergence does not occur, e.g., within a set time period, the state of the non-volatile storage element is sensed again, current values of the reliability metrics in the decoder are adjusted, and the decoding again attempts to converge. In another approach, the initial reliability metrics are based on multiple reads. Tables which store the reliability metrics and adjustments based on the sensed states can be prepared before decoding occurs. | 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 |
20080266973 | REDUCING POWER CONSUMPTION DURING READ OPERATIONS IN NON-VOLATILE STORAGE - Power consumption in a non-volatile storage device is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line. | 10-30-2008 |
20080266975 | NON-VOLATILE STORAGE WITH REDUCED POWER CONSUMPTION DURING READ OPERATIONS - A non-volatile storage device in which power consumption is reduced by providing reduced read pass voltages on unselected word lines during a read operation. A programming status of one or more unselected word lines which are after a selected word line on which storage elements are being read is checked to determine whether the unselected word lines contain programmed storage elements. When an unprogrammed word line is identified, reduced read pass voltages are provided on that word line and other word lines which are after that word line in a programming order. The programming status can be determined by a flag stored in the word line, for instance, or by reading the word line at the lowest read state. The unselected word lines which are checked can be predetermined in a set of word lines, or determined adaptively based on a position of the selected word line. | 10-30-2008 |
20080273388 | ADJUSTING RESISTANCE OF NON-VOLATILE MEMORY USING DUMMY MEMORY CELLS - In some non-volatile storage systems, a block of data memory cells is manufactured with a dummy word line at the bottom of the block, at the top of the block, and/or at other locations. By selectively programming memory cells on the dummy word line(s), the resistances associated with the data memory cells can be changed to account for different programmed data patterns. | 11-06-2008 |
20080304316 | SENSING WITH BIT-LINE LOCKOUT CONTROL IN NON-VOLATILE MEMORY - In sensing a group of cells in a multi-state nonvolatile memory, multiple sensing cycles relative to different demarcation threshold levels are needed to resolve all possible multiple memory states. Each sensing cycle has a sensing pass. It may also include a pre-sensing pass or sub-cycle to identify the cells whose threshold voltages are below the demarcation threshold level currently being sensed relative to. These are higher current cells which can be turned off to achieve power-saving and reduced source bias errors. The cells are turned off by having their associated bit lines locked out to ground. A repeat sensing pass will then produced more accurate results. Circuitry and methods are provided to selectively enable or disable bit-line lockouts and pre-sensing in order to improving performance while ensuring the sensing operation does not consume more than a maximum current level. | 12-11-2008 |
20080304325 | NON-VOLATILE MEMORY WITH IMPROVED SENSING HAVING BIT-LINE LOCKOUT CONTROL - In sensing a group of cells in a multi-state nonvolatile memory, multiple sensing cycles relative to different demarcation threshold levels are needed to resolve all possible multiple memory states. Each sensing cycle has a sensing pass. It may also include a pre-sensing pass or sub-cycle to identify the cells whose threshold voltages are below the demarcation threshold level currently being sensed relative to. These are higher current cells which can be turned off to achieve power-saving and reduced source bias errors. The cells are turned off by having their associated bit lines locked out to ground. A repeat sensing pass will then produced more accurate results. Circuitry and methods are provided to selectively enable or disable bit-line lockouts and pre-sensing in order to improving performance while ensuring the sensing operation does not consume more than a maximum current level. | 12-11-2008 |
20080318381 | METHODS OF FORMING HIGH DENSITY SEMICONDUCTOR DEVICES USING RECURSIVE SPACER TECHNIQUE - High density semiconductor devices and methods of fabricating the same are disclosed. Spacer fabrication techniques are utilized to form circuit elements having reduced feature sizes, which may be smaller than the smallest lithographically resolvable element size of the process being used. A first set of spacers may be processed to provide planar and parallel sidewalls. A second set of spacers may be formed on planar and parallel sidewalls of the first set of spacers. The second set of spacers serve as a mask to form one or more circuit elements in a layer beneath the second set of spacers. The steps according to embodiments of the invention allow a recursive spacer technique to be used which results in robust, evenly spaced, spacers to be formed and used as masks for the circuit elements. | 12-25-2008 |
20090003025 | DUAL BIT LINE METAL LAYERS FOR NON-VOLATILE MEMORY - Structures and techniques are disclosed for reducing bit line to bit line capacitance in a non-volatile storage system. The bit lines are formed at a 4 f pitch in each of two separate metal layers, and arranged to alternate between each of the layers. In an alternative embodiment, shields are formed between each of the bit lines on each metal layer. | 01-01-2009 |
20090004843 | METHOD FOR FORMING DUAL BIT LINE METAL LAYERS FOR NON-VOLATILE MEMORY - Structures and techniques are disclosed for reducing bit line to bit line capacitance in a non-volatile storage system. The bit lines are formed at a 4f pitch in each of two separate metal layers, and arranged to alternate between each of the layers. In an alternative embodiment, shields are formed between each of the bit lines on each metal layer. | 01-01-2009 |
20090067244 | NONVOLATILE MEMORY AND METHOD FOR ON-CHIP PSEUDO-RANDOMIZATION OF DATA WITHIN A PAGE AND BETWEEN PAGES - Features within an integrated-circuit memory chip enables scrambling or randomization of data stored in an array of nonvolatile memory cells. In one embodiment, randomization within each page helps to control source loading errors during sensing and floating gate to floating gate coupling among neighboring cells. Randomization from page to page helps to reduce program disturbs, user read disturbs, and floating gate to floating gate coupling that result from repeated and long term storage of specific data patterns. In another embodiment, randomization is implemented both within a page and between pages. The scrambling or randomization may be predetermined, or code generated pseudo randomization or user driven randomization in different embodiments. These features are accomplished within the limited resource and budget of the integrated-circuit memory chip. | 03-12-2009 |
20090080229 | SINGLE-LAYER METAL CONDUCTORS WITH MULTIPLE THICKNESSES - A pattern that includes trenches of different depths is formed on a substrate using nanoimprint lithography. A subsequent metal deposition forms lines of different thicknesses according to trench depth, from a single metal layer. Vias extending down from lines are also formed from the same layer. Individual bit lines are formed having different thicknesses at different locations. | 03-26-2009 |
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 |
20090086544 | COMPENSATION OF NON-VOLATILE MEMORY CHIP NON-IDEALITIES BY PROGRAM PULSE ADJUSTMENT - 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 pulse widths that vary as a function of simulated pulse magnitude data. The programming pulses can also have pulse magnitudes that vary based on measurements taken while testing the set of non-volatile storage elements. In one embodiment, the pulse widths are determined after simulation performed prior to fabrication of the non-volatile storage elements. In another embodiment, the pulse magnitudes are calculated after fabrication of the non-volatile storage elements. | 04-02-2009 |
20090097319 | APPLYING ADAPTIVE BODY BIAS TO NON-VOLATILE STORAGE BASED ON NUMBER OF PROGRAMMING CYCLES - Body bias can be applied to optimize performance in a non-volatile storage system. Body bias can be set in an adaptive manner to reduce an error count of an error correcting and/or detecting code when reading data from non-volatile storage elements. Also, a body bias level can be increased or decreased as a number of programming cycles increases. Also, body bias levels can be set and applied separately for a chip, plane, block and/or page. A body bias can be applied to a first set of NAND strings for which operations are being performed by controlling a first voltage provided to a source side of the first set of NAND strings and a second voltage provided to a p-well. A source side of a second set of NAND strings for which operations are not being performed is floated or receives a fixed voltage. | 04-16-2009 |
20090103356 | NON-REAL TIME REPROGRAMMING OF NON-VOLATILE MEMORY TO ACHIEVE TIGHTER DISTRIBUTION OF THRESHOLD VOLTAGES - A set of non-volatile storage elements undergoes initial programming, after which a reprogramming, with higher verify levels, is performed in non-real time, such as when a control enters a standby mode, when no other read or write tasks are pending. The reprogramming can program pages in the set one at a time, stopping at a page boundary when another read or write task is pending, and restarting when the control become available again. Status flags can be provided to identify whether a page and/or the set has completed the reprogramming. In another aspect, a higher pass voltage is applied to unselected word lines during the reprogramming. In another aspect, an error count is determined using a default set of read voltages, and an alternative set of read voltages is selected if the count exceeds a threshold. | 04-23-2009 |
20090129159 | READ OPERATION FOR NON-VOLATILE STORAGE WITH COMPENSATION FOR COUPLING - Shifts in the apparent charge stored on a floating gate (or other charge storing element) of a non-volatile memory cell can occur because of the coupling of an electric field based on the charge stored in adjacent floating gates (or other adjacent charge storing elements). The problem occurs most pronouncedly between sets of adjacent memory cells that have been programmed at different times. To account for this coupling, the read process for a particular memory cell will provide compensation to an adjacent memory cell in order to reduce the coupling effect that the adjacent memory cell has on the particular memory cell. | 05-21-2009 |
20090129160 | READ OPERATION FOR NON-VOLATILE STORAGE WITH COMPENSATION FOR COUPLING - Shifts in the apparent charge stored on a floating gate (or other charge storing element) of a non-volatile memory cell can occur because of the coupling of an electric field based on the charge stored in adjacent floating gates (or other adjacent charge storing elements). The problem occurs most pronouncedly between sets of adjacent memory cells that have been programmed at different times. To account for this coupling, the read process for a particular memory cell will provide compensation to an adjacent memory cell in order to reduce the coupling effect that the adjacent memory cell has on the particular memory cell. | 05-21-2009 |
20090147586 | Non-Volatile Memory and Method With Improved Sensing Having Bit-Line Lockout Control - In sensing a group of cells in a multi-state nonvolatile memory, multiple sensing cycles relative to different demarcation threshold levels are needed to resolve all possible multiple memory states. Each sensing cycle has a sensing pass. It may also include a pre-sensing pass or sub-cycle to identify the cells whose threshold voltages are below the demarcation threshold level currently being sensed relative to. These are higher current cells which can be turned off to achieve power-saving and reduced source bias errors. The cells are turned off by having their associated bit lines locked out to ground. A repeat sensing pass will then produced more accurate results. Circuitry and methods are provided to selectively enable or disable bit-line lockouts and pre-sensing in order to improving performance while ensuring the sensing operation does not consume more than a maximum current level. | 06-11-2009 |
20090161433 | Regulation of Source Potential to Combat Cell Source IR Drop - Techniques are presented for dealing with possible source line bias is an error introduced by a non-zero resistance in the ground loop of the read/write circuits of a non-volatile memory. The error is caused by a voltage drop across the resistance of the source path to the chip's ground when current flows. For this purpose, the memory device includes a source potential regulation circuit, including an active circuit element having a first input connected to a reference voltage and having a second input connected as a feedback loop that is connectable to the aggregate node from which the memory cells of a structural block have their current run to ground. A variation includes a non-linear resistive element connectable between the aggregate node and ground. | 06-25-2009 |
20090244977 | VARIABLE INITIAL PROGRAM VOLTAGE MAGNITUDE FOR NON-VOLATILE STORAGE - Multiple programming processes are performed for a plurality of non-volatile storage elements. Each of the programming process operates to program at least a subset of said non-volatile storage elements to a set of target conditions using program pulses. In one embodiment, a first programming pass includes soft programming and additional programming passes include the programming of data. In another embodiment, all of the programming process includes programming data. For at least a subset of said programming processes, a program pulse associated with achieving a particular result for a respective programming process is identified. The identified program pulse is used to adjust programming for a subsequent programming process. | 10-01-2009 |
20090282186 | DYNAMIC AND ADAPTIVE OPTIMIZATION OF READ COMPARE LEVELS BASED ON MEMORY CELL THRESHOLD VOLTAGE DISTRIBUTION - A process is performed periodically or in response to an error in order to dynamically and adaptively optimize read compare levels based on memory cell threshold voltage distribution. One embodiment of the process includes determining threshold voltage distribution data for a population of non-volatile storage elements, smoothing the threshold voltage distribution data using a weighting function to create an interim set of data, determining a derivative of the interim set of data, and identifying and storing negative to positive zero crossings of the derivative as read compare points. | 11-12-2009 |
20090323412 | READ DISTURB MITIGATION IN NON-VOLATILE MEMORY - Read disturb is reduced in non-volatile storage. In one aspect, when a read command is received from a host for reading a selected word line, a word line which is not selected for reading is randomly chosen and its storage elements are sensed to determine optimized read compare levels for reading the selected word line. Or, a refresh operation may be indicated for the entire block based on an error correction metric obtained in reading the storage elements of the chosen word line. This is useful especially when the selected word line is repeatedly selected for reading, exposing the other word lines to additional read disturb. In another aspect, when multiple data states are stored, one read compare level is obtained from sensing, e.g., from a threshold voltage distribution, and other read compare levels are derived from a formula. | 12-31-2009 |
20100014349 | PROGRAMMING NON-VOLATILE STORAGE USING BINARY AND MULTI-STATE PROGRAMMING PROCESSES - A non-volatile storage system stores data by programming the data as binary data into blocks that have not yet been programmed with multi-state data and have not yet been programmed with binary data X times. The system transfers data from multiple blocks (source blocks) of binary data to one block (target block) of multi-state data using a multi-state programming process, where the target block has been previously programmed with binary data X times (or less than X times). | 01-21-2010 |
20100024732 | Systems for Flash Heating in Atomic Layer Deposition - System and methods for flash heating of materials deposited using atomic layer deposition techniques are disclosed. By flash heating the surface of the deposited material after each or every few deposition cycles, contaminants such as un-reacted precursors and byproducts can be released from the deposited material. A higher quality material is deposited by reducing the incorporation of impurities. A flash heating source is capable of quickly raising the temperature of the surface of a deposited material without substantially raising the temperature of the bulk of the substrate on which the material is being deposited. Because the temperature of the bulk of the substrate is not significantly raised, the bulk acts like a heat sink to aid in cooling the surface after flash heating. In this manner, processing times are not significantly increased in order to allow the surface temperature to reach a suitably low temperature for deposition. | 02-04-2010 |
20100039859 | System and Method for Programming Cells in Non-Volatile Integrated Memory Devices - A system and method for quickly and efficiently programming hard-to-program storage elements in non-volatile integrated memory devices is presented. A number of storage elements are simultaneously subjected to a programming process with the current flowing through the storage elements limited to a first level. As a portion of these storage elements reach a prescribed state, they are removed from the set of cells being programmed and the current limit on the elements that continue to be programmed is raised. The current level in these hard-to-program cells can be raised to a second, higher limit or unregulated. According to another aspect, during a program operation the current limit allowed for a cell depends upon the target state to which it is to be programmed. | 02-18-2010 |
20100047979 | METHOD OF REDUCING COUPLING BETWEEN FLOATING GATES IN NONVOLATILE MEMORY - A nonvolatile memory array includes floating gates that have an inverted-T shape in cross section along a plane that is perpendicular to the direction along which floating cells are connected together to form a string. Adjacent strings are isolated by shallow trench isolation structures. | 02-25-2010 |
20100074018 | READ OPERATION FOR NON-VOLATILE STORAGE WITH COMPENSATION FOR COUPLING - Shifts in the apparent charge stored on a floating gate (or other charge storing element) of a non-volatile memory cell can occur because of the coupling of an electric field based on the charge stored in adjacent floating gates (or other adjacent charge storing elements). The problem occurs most pronouncedly between sets of adjacent memory cells that have been programmed at different times. To account for this coupling, the read process for a particular memory cell will provide compensation to an adjacent memory cell in order to reduce the coupling effect that the adjacent memory cell has on the particular memory cell. | 03-25-2010 |
20100128525 | ALL-BIT-LINE ERASE VERIFY AND SOFT PROGRAM VERIFY - Techniques are disclosed herein for verifying that memory cells comply with a target threshold voltage that is negative. The technique can be used for an erase verify or a soft program verify. One or more erase pulses are applied to a group of non-volatile storage elements that are associated with bit lines and word lines. One or more non-negative compare voltages (e.g., zero volts) are applied to at least a portion of the word lines after applying the erase pulses. Conditions on the bit lines are sensed while holding differences between voltages on the bit lines substantially constant and while applying the one or more compare voltages. A determination is made whether the group is sufficiently erased based on the conditions. At least one additional erase pulse is applied to the group of non-volatile storage elements if the group of non-volatile storage elements are not sufficiently erased. | 05-27-2010 |
20100149876 | Reverse Reading In Non-Volatile Memory With Compensation For Coupling - Shifts in the apparent charge stored by a charge storage region such as a floating gate in a non-volatile memory cell can occur because of electrical field coupling based on charge stored in adjacent (or other) charge storage regions. Although not exclusively, the effects are most pronounced in situations where adjacent memory cells are programmed after a selected memory cell. To account for the shift in apparent charge, one or more compensations are applied when reading storage elements of a selected word line based on the charge stored by storage elements of other word lines. Efficient compensation techniques are provided by reverse reading blocks (or portions thereof) of memory cells. By reading in the opposite direction of programming, the information needed to apply (or select the results of) an appropriate compensation when reading a selected cell is determined during the actual read operation for the adjacent word line rather than dedicating a read operation to determine the information. | 06-17-2010 |
20100157671 | DATA REFRESH FOR NON-VOLATILE STORAGE - Techniques are disclosed to refresh data in a non-volatile storage device often enough to combat erroneous or corrupted data bits, but not so often as to interfere with memory access or to cause excessive stress on the memory cells. One embodiment includes determining to perform a refresh of data stored in a first group of non-volatile storage elements in a device based on a condition of data in the first group, determining that a second group of non-volatile storage elements in the device should undergo a refresh procedure based on when the second group of non-volatile storage elements were last programmed relative to when the first group of non-volatile storage elements were last programmed, and performing the refresh procedure on the second group of non-volatile storage element. | 06-24-2010 |
20100157678 | NON-VOLATILE MEMORY WITH BOOST STRUCTURES - A non-volatile memory having boost structures. Boost structures are provided for individual NAND strings and can be individually controlled to assist in programming, verifying and reading processes. The boost structures can be commonly boosted and individually discharged, in part, based on a target programming state or verify level. The boost structures assists in programming so that the programming and pass voltage on a word line can be reduced, thereby reducing side effects such as program disturb. During verifying, all storage elements on a word line can be verified concurrently. The boost structure can also assist during reading. In one approach, the NAND string has dual source-side select gates between which the boost structure contacts the substrate at a source/drain region, and a boost voltage is provided to the boost structure via a source-side of the NAND string. | 06-24-2010 |
20100195398 | APPLYING DIFFERENT BODY BIAS TO DIFFERENT SUBSTRATE PORTIONS FOR NON-VOLATILE STORAGE - Body bias can be applied to optimize performance in a non-volatile storage system. Body bias can be set in an adaptive manner to reduce an error count of an error correcting and/or detecting code when reading data from non-volatile storage elements. Also, a body bias level can be increased or decreased as a number of programming cycles increases. Also, body bias levels can be set and applied separately for a chip, plane, block and/or page. A body bias can be applied to a first set of NAND strings for which operations are being performed by controlling a first voltage provided to a source side of the first set of NAND strings and a second voltage provided to a p-well. A source side of a second set of NAND strings for which operations are not being performed is floated or receives a fixed voltage. | 08-05-2010 |
20100202207 | ALL-BIT-LINE ERASE VERIFY AND SOFT PROGRAM VERIFY - Techniques are disclosed herein for verifying that memory cells comply with a target threshold voltage that is negative. The technique can be used for an erase verify or a soft program verify. One or more erase pulses are applied to a group of non-volatile storage elements that are associated with bit lines and word lines. One or more non-negative compare voltages (e.g., zero volts) are applied to at least a portion of the word lines after applying the erase pulses. Conditions on the bit lines are sensed while holding differences between voltages on the bit lines substantially constant and while applying the one or more compare voltages. A determination is made whether the group is sufficiently erased based on the conditions. At least one additional erase pulse is applied to the group of non-volatile storage elements if the group of non-volatile storage elements are not sufficiently erased. | 08-12-2010 |
20100226182 | METHODS OF FORMING AND OPERATING NAND MEMORY WITH SIDE-TUNNELING - A string of nonvolatile memory cells are formed with control gates extending between floating gates, control gates and floating gates separated by tunnel dielectric layers. Electron tunneling between control gates and floating gates is used for programming. A process for forming a memory array forms odd numbered floating gates from a first layer and even numbered floating gates from a second layer. | 09-09-2010 |
20100259987 | Two Pass Erase For Non-Volatile Storage - Techniques are disclosed herein for erasing non-volatile memory cells. The memory cells are erased using a trial erase pulse. A suitable magnitude for a second pulse is determined based on the magnitude of the trial erase pulse and data collected about the threshold voltage distribution after the trial erase. The second erase pulse is used to erase the memory cells. In one implementation, the threshold voltages of the memory cells are not verified after the second erase. Soft programming after the second erase may be performed. The magnitude of the soft programming pulse may be determined based on the trial erase pulse. In one implementation, the memory cells' threshold voltages are not verified after the soft programming. Limiting the number of erase pulses and soft programming pulses saves time and power. Determining an appropriate magnitude for the second erase pulse minimizes or eliminates over-erasing. | 10-14-2010 |
20100271874 | READ DISTURB MITIGATION IN NON-VOLATILE MEMORY - Read disturb is reduced in non-volatile storage. In one aspect, when a read command is received from a host for reading a selected word line, a word line which is not selected for reading is randomly chosen and its storage elements are sensed to determine optimized read compare levels for reading the selected word line. Or, a refresh operation may be indicated for the entire block based on an error correction metric obtained in reading the storage elements of the chosen word line. This is useful especially when the selected word line is repeatedly selected for reading, exposing the other word lines to additional read disturb. In another aspect, when multiple data states are stored, one read compare level is obtained from sensing, e.g., from a threshold voltage distribution, and other read compare levels are derived from a formula. | 10-28-2010 |
20100277983 | Two Pass Erase For Non-Volatile Storage - Techniques are disclosed herein for erasing non-volatile memory cells. A subset of the memory cells are pre-conditioned prior to erase. The pre-conditioning alters the threshold voltage of the memory cells in a way that may help make later calculations more accurate. As an example, memory cells along a single word line might be pre-conditioned. After the pre-conditioning, the memory cells are erased using a trial erase pulse. A suitable magnitude for a second pulse is determined based on the magnitude of the trial erase pulse and data collected about the threshold voltage distribution after the trial erase. The second erase pulse is used to erase the memory cells. Determining an appropriate magnitude for the second erase pulse minimizes or eliminates over-erasing. | 11-04-2010 |
20110019484 | Non-Volatile Memory and Method With Improved Sensing Having Bit-Line Lockout Control - In sensing a group of cells in a multi-state nonvolatile memory, multiple sensing cycles relative to different demarcation threshold levels are needed to resolve all possible multiple memory states. Each sensing cycle has a sensing pass. It may also include a pre-sensing pass or sub-cycle to identify the cells whose threshold voltages are below the demarcation threshold level currently being sensed relative to. These are higher current cells which can be turned off to achieve power-saving and reduced source bias errors. The cells are turned off by having their associated bit lines locked out to ground. A repeat sensing pass will then produced more accurate results. Circuitry and methods are provided to selectively enable or disable bit-line lockouts and pre-sensing in order to improving performance while ensuring the sensing operation does not consume more than a maximum current level. | 01-27-2011 |
20110026353 | DATA REFRESH FOR NON-VOLATILE STORAGE - Techniques are disclosed to refresh data in a non-volatile storage device often enough to combat erroneous or corrupted data bits, but not so often as to interfere with memory access or to cause excessive stress on the memory cells. One embodiment includes determining to perform a refresh of data stored in a first group of non-volatile storage elements in a device based on a condition of data in the first group, determining that a second group of non-volatile storage elements in the device should undergo a refresh procedure based on when the second group of non-volatile storage elements were last programmed relative to when the first group of non-volatile storage elements were last programmed, and performing the refresh procedure on the second group of non-volatile storage element. | 02-03-2011 |
20110063918 | IDENTIFYING AT-RISK DATA IN NON-VOLATILE STORAGE - The non-volatile storage system predicts which blocks (or other units of storage) will become bad based on performance data. User data in those blocks predicted to become bad can be re-programmed to other blocks, and the blocks predicted to become bad can be removed from further use. | 03-17-2011 |
20110111583 | METHOD OF REDUCING COUPLING BETWEEN FLOATING GATES IN NONVOLATILE MEMORY - A nonvolatile memory array includes floating gates that have an inverted-T shape in cross section along a plane that is perpendicular to the direction along which floating cells are connected together to form a string. Adjacent strings are isolated by shallow trench isolation structures. | 05-12-2011 |
20110131473 | Method For Decoding Data In Non-Volatile Storage Using Reliability Metrics Based On Multiple Reads - Data stored in non-volatile storage is decoded using iterative probabilistic decoding and multiple read operations to achieve greater reliability. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding read data of a set of non-volatile storage element. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. If convergence does not occur, e.g., within a set time period, the state of the non-volatile storage element is sensed again, current values of the reliability metrics in the decoder are adjusted, and the decoding again attempts to converge. | 06-02-2011 |
20110141810 | READ OPERATION FOR NON-VOLATILE STORAGE WITH COMPENSATION FOR COUPLING - Shifts in the apparent charge stored on a floating gate (or other charge storing element) of a non-volatile memory cell can occur because of the coupling of an electric field based on the charge stored in adjacent floating gates (or other adjacent charge storing elements). The problem occurs most pronouncedly between sets of adjacent memory cells that have been programmed at different times. To account for this coupling, the read process for a particular memory cell will provide compensation to an adjacent memory cell in order to reduce the coupling effect that the adjacent memory cell has on the particular memory cell. | 06-16-2011 |
20110194348 | DYNAMIC AND ADAPTIVE OPTIMIZATION OF READ COMPARE LEVELS BASED ON MEMORY CELL THRESHOLD VOLTAGE DISTRIBUTION - A process is performed periodically or in response to an error in order to dynamically and adaptively optimize read compare levels based on memory cell threshold voltage distribution. One embodiment of the process includes determining threshold voltage distribution data for a population of non-volatile storage elements, smoothing the threshold voltage distribution data using a weighting function to create an interim set of data, determining a derivative of the interim set of data, and identifying and storing negative to positive zero crossings of the derivative as read compare points. | 08-11-2011 |
20110225473 | READ OPERATION FOR NON-VOLATILE STORAGE WITH COMPENSATION FOR COUPLING - Shifts in the apparent charge stored on a floating gate (or other charge storing element) of a non-volatile memory cell can occur because of the coupling of an electric field based on the charge stored in adjacent floating gates (or other adjacent charge storing elements). The problem occurs most pronouncedly between sets of adjacent memory cells that have been programmed at different times. To account for this coupling, the read process for a particular memory cell will provide compensation to an adjacent memory cell in order to reduce the coupling effect that the adjacent memory cell has on the particular memory cell. | 09-15-2011 |
20110235420 | SIMULTANEOUS MULTI-STATE READ OR VERIFY IN NON-VOLATILE STORAGE - Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. | 09-29-2011 |
20110235428 | COMPENSATION OF NON-VOLATILE MEMORY CHIP NON-IDEALITIES BY PROGRAM PULSE ADJUSTMENT - 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 pulse widths that vary as a function of simulated pulse magnitude data. The programming pulses can also have pulse magnitudes that vary based on measurements taken while testing the set of non-volatile storage elements. In one embodiment, the pulse widths are determined after simulation performed prior to fabrication of the non-volatile storage elements. In another embodiment, the pulse magnitudes are calculated after fabrication of the non-volatile storage elements. | 09-29-2011 |
20110252283 | Soft Bit Data Transmission For Error Correction Control In Non-Volatile Memory - Data stored in non-volatile storage is decoded using iterative probabilistic decoding. An error correcting code such as a low density parity check code may be used. In one approach, initial reliability metrics, such as logarithmic likelihood ratios, are used in decoding sensed states of a set of non-volatile storage element. The decoding attempts to converge by adjusting the reliability metrics for bits in code words which represent the sensed state. Soft data bits are read from the memory if the decoding fails to converge. Initial reliability metric values are provided after receiving the hard read results and at each phase of the soft bit operation(s). In one embodiment, a second soft bit is read from the memory using multiple subsets of soft bit compare levels. While reading at the second subset of compare levels, decoding can be performed based on the first subset data. | 10-13-2011 |
20110267887 | Reducing Energy Consumption When Applying Body Bias To Substrate Having Sets Of Nand Strings - Body bias can be applied to optimize performance in a non-volatile storage system. Body bias can be set in an adaptive manner to reduce an error count of an error correcting and/or detecting code when reading data from non-volatile storage elements. Also, a body bias level can be increased or decreased as a number of programming cycles increases. Also, body bias levels can be set and applied separately for a chip, plane, block and/or page. A body bias can be applied to a first set of NAND strings for which operations are being performed by controlling a first voltage provided to a source side of the first set of NAND strings and a second voltage provided to a p-well. A source side of a second set of NAND strings for which operations are not being performed is floated or receives a fixed voltage. | 11-03-2011 |
20110286265 | PROGRAMMING NON-VOLATILE STORAGE WITH SYNCHONIZED COUPLING - A process for programming non-volatile storage is able to achieve faster programming speeds and/or more accurate programming through synchronized coupling of neighboring word lines. The process for programming includes raising voltages for a set of word lines connected a group of connected non-volatile storage elements. The set of word lines include a selected word line, unselected word lines that are adjacent to the selected word line and other unselected word lines. After raising voltages for the set of word lines, the process includes raising the selected word line to a program voltage and raising the unselected word lines that are adjacent to the selected word line to one or more voltage levels concurrently with the raising the selected word line to the program voltage. The program voltage causes at least one of the non-volatile storage elements to experience programming. | 11-24-2011 |
20120039124 | Non-Volatile Memory and Method With Improved Sensing Having Bit-Line Lockout Control - In sensing a group of cells in a multi-state nonvolatile memory, multiple sensing cycles relative to different demarcation threshold levels are needed to resolve all possible multiple memory states. Each sensing cycle has a sensing pass. It may also include a pre-sensing pass or sub-cycle to identify the cells whose threshold voltages are below the demarcation threshold level currently being sensed relative to. These are higher current cells which can be turned off to achieve power-saving and reduced source bias errors. The cells are turned off by having their associated bit lines locked out to ground. A repeat sensing pass will then produced more accurate results. Circuitry and methods are provided to selectively enable or disable bit-line lockouts and pre-sensing in order to improving performance while ensuring the sensing operation does not consume more than a maximum current level. | 02-16-2012 |
20120120726 | VARIABLE INITIAL PROGRAM VOLTAGE MAGNITUDE FOR NON-VOLATILE STORAGE - Multiple programming processes are performed for a plurality of non-volatile storage elements. Each of the programming process operates to program at least a subset of said non-volatile storage elements to a set of target conditions using program pulses. In one embodiment, a first programming pass includes soft programming and additional programming passes include the programming of data. In another embodiment, all of the programming process includes programming data. For at least a subset of said programming processes, a program pulse associated with achieving a particular result for a respective programming process is identified. The identified program pulse is used to adjust programming for a subsequent programming process. | 05-17-2012 |
20120147676 | NON-VOLATILE STORAGE SYSTEM WITH SHARED BIT LINES CONNECTED TO SINGLE SELECTION DEVICE - A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. | 06-14-2012 |
20120163085 | Non-Volatile Memory And Methods With Soft-Bit Reads While Reading Hard Bits With Compensation For Coupling - A non-volatile memory has its cells' thresholds programmed within any one of a first set of voltage bands partitioned by a first set of reference thresholds across a threshold window. Hard bits are obtained when read relative to the first set of reference thresholds. The cells are read at a higher resolution relative to a second set of reference thresholds so as to provide additional soft bits for error correction. The soft bits are generated by a combination of a first modulation of voltage on a current word line WLn and a second modulation of voltage on an adjacent word line WLn+1, as in a reading scheme known as “Direct-Lookahead (DLA)”. | 06-28-2012 |
20120250415 | SIMULTANEOUS MULTI-STATE READ OR VERIFY IN NON-VOLATILE STORAGE - Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. | 10-04-2012 |
20120314502 | PROGRAMMING NON-VOLATILE STORAGE WITH SYNCHONIZED COUPLING - A process for programming non-volatile storage is able to achieve faster programming speeds and/or more accurate programming through synchronized coupling of neighboring word lines. The process for programming includes raising voltages for a set of word lines connected a group of connected non-volatile storage elements. The set of word lines include a selected word line, unselected word lines that are adjacent to the selected word line and other unselected word lines. After raising voltages for the set of word lines, the process includes raising the selected word line to a program voltage and raising the unselected word lines that are adjacent to the selected word line to one or more voltage levels concurrently with the raising the selected word line to the program voltage. The program voltage causes at least one of the non-volatile storage elements to experience programming. | 12-13-2012 |
20120327716 | COMPENSATION OF NON-VOLATILE MEMORY CHIP NON-IDEALITIES BY PROGRAM PULSE ADJUSTMENT - 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 pulse widths that vary as a function of simulated pulse magnitude data. The programming pulses can also have pulse magnitudes that vary based on measurements taken while testing the set of non-volatile storage elements. In one embodiment, the pulse widths are determined after simulation performed prior to fabrication of the non-volatile storage elements. In another embodiment, the pulse magnitudes are calculated after fabrication of the non-volatile storage elements. | 12-27-2012 |
20130105881 | Self-Aligned Planar Flash Memory And Methods Of Fabrication | 05-02-2013 |
20130128665 | NON-VOLATILE STORAGE WITH BROKEN WORD LINE SCREEN AND DATA RECOVERY - Data, normally read using a page-by page read process, can be recovered from memory cells connected to a broken word line by performing a sequential read process. To determine whether a word line is broken, both a page-by page read process and a sequential read process are performed. The results of both read processes are compared. If the number of mismatches between the two read processes is greater than a threshold, it is concluded that there is a broken word line. | 05-23-2013 |
20130128669 | OPERATION FOR NON-VOLATILE STORAGE SYSTEM WITH SHARED BIT LINES - A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential. | 05-23-2013 |
20130246720 | Providing Reliability Metrics For Decoding Data In Non-Volatile Storage - A set of reliability metrics is provided for use by an iterative probabilistic decoding process for non-volatile storage. A plurality of sense operations are performed on at least one set of non-volatile storage elements which are programmed to a plurality of programming states. A set of reliability metrics such as logarithmic likelihood ratios is provided based on the sense operations. The set of reliability metrics is can be used by an iterative probabilistic decoding process in determining a programming state of at least one non-volatile storage element based on at least one subsequent sense operation involving the at least one non-volatile storage element. The plurality of sense operations can be performed at different ages (e.g., number of program/erase cycles) of the at least one set of non-volatile storage elements and the set of reliability metrics can be based on an average over the different ages. | 09-19-2013 |
20130294169 | SIMULTANEOUS MULTI-LEVEL BINARY SEARCH IN NON-VOLATILE STORAGE - Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. A binary search may be performed. | 11-07-2013 |
20130308381 | NON-VOLATILE MEMORY AND METHODS WITH SOFT-BIT READS WHILE READING HARD BITS WITH COMPENSATION FOR COUPLING - A non-volatile memory has its cells' thresholds programmed within any one of a first set of voltage bands partitioned by a first set of reference thresholds across a threshold window. Hard bits are obtained when read relative to the first set of reference thresholds. The cells are read at a higher resolution relative to a second set of reference thresholds so as to provide additional soft bits for error correction. The soft bits are generated by a combination of a first modulation of voltage on a current word line WLn and a second modulation of voltage on an adjacent word line WLn+1, as in a reading scheme known as “Direct-Lookahead (DLA)”. | 11-21-2013 |
20140269082 | OPERATION FOR NON-VOLATILE STORAGE SYSTEM WITH SHARED BIT LINES - A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential. | 09-18-2014 |
20140362646 | READING SOFT BITS SIMULTANEOUSLY - Methods and devices for simultaneously verifying or reading multiple states in non-volatile storage are disclosed. Methods and devices for efficiently reducing or eliminating cross-coupling effects in non-volatile storage are disclosed. Methods and devices for efficiently performing reads at a number of voltages to search for the threshold voltage of a memory cell are disclosed. Memory cells on different NAND strings that are read at the same time may be tested for different threshold voltage levels. Memory cells may be tested for different threshold voltages by applying different gate-to-source voltages to memory cells being tested for different threshold voltages. Memory cells may be tested for different threshold voltages by applying different drain to source voltages to the memory cells. Different amounts of compensation for cross-coupling affects may be applied to memory cells on different NAND strings that are read or programmed at the same time. A binary search may be performed. | 12-11-2014 |