Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.

Abstract: In a non-volatile storage system, first and second substrate channel regions for an unselected NAND string are boosted during programming to inhibit program disturb. The first and second substrate channel regions are created on either side of an isolation word line. During a program pulse time period in which a program pulse is applied to a selected word line, a voltage applied to an unselected word line which extends directly over the second channel region is stepped up to a respective pre-program pulse voltage, at a faster rate at which a voltage applied to an unselected word line which extends directly over the first channel region is stepped up to a respective pre-program pulse voltage. This helps improve the isolation between the channel regions.

Abstract: Non-voltage storage and techniques for fabricating non-volatile storage are disclosed. In some embodiments, at least a portion of the control gates of non-volatile storage elements are formed from p-type polysilicon. In one embodiment, a lower portion of the control gate is p-type polysilicon. The upper portion of the control gate could be p-type polysilicon, n-type polysilicon, metal, metal nitride, etc. P-type polysilicon in the control gate may not deplete even at high Vpgm. Therefore, a number of problems that could occur if the control gate depleted are mitigated. For example, a memory cell having a control gate that is at least partially p-type polysilicon might be programmed with a lower Vpgm than a memory cell formed from n-type polysilicon.

Abstract: 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.

Abstract: In a non-volatile storage system, one or more substrate channel regions for an unselected NAND string are boosted during programming to inhibit program disturb. A voltage applied to one or more unselected word lines associated with at least a first channel region is increased during a program pulse time period in which a program pulse is applied to a selected word line. The increase can be gradual, in the form of a ramp, or step-wise. The boosting level of the first channel region can be maintained. The increase in the voltage applied to the one or more unselected word lines can vary with temperature as well. Before the program pulse time period, the voltage applied to the one or more unselected word lines can be ramped up at a faster rate for a second, adjacent channel region than for the first channel region, to help isolate the channel regions.

Abstract: High-density semiconductor memory utilizing metal control gate structures and air gap electrical isolation between discrete devices in these types of structures are provided. During gate formation and definition, etching the metal control gate layer(s) is separated from etching the charge storage layer to form protective sidewall spacers along the vertical sidewalls of the metal control gate layer(s). The sidewall spacers encapsulate the metal control gate layer(s) while etching the charge storage material to avoid contamination of the charge storage and tunnel dielectric materials. Electrical isolation is provided, at least in part, by air gaps that are formed in the row direction and/or air gaps that are formed in the column direction.

Abstract: To program a set of non-volatile storage elements, a set of programming pulses are applied to the control gates (or other terminals) of the non-volatile storage elements. The programming pulses have 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.

Abstract: 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.

Abstract: 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.

Abstract: In a programming operation, selected storage elements which reach a lockout condition are subject to reduced channel boosting in a program portion of the next program-verify iteration, to reduce coupling effects on the storage elements which continue to be programmed. In subsequent program-verify iterations, the locked out storage elements are subject to full channel boosting. Or, the boosting can be stepped up over multiple program-verify iterations after lockout. The amount of channel boosting can be set by adjusting the timing of a channel pre-charge operation and by stepping up pass voltages which are applied to unselected word lines. The reduced channel boosting can be implemented for a range of program-verify iterations where the lockout condition is most likely to be first reached, for one or more target data states.

Abstract: To program a set of non-volatile storage elements, a set of programming pulses are applied to the control gates (or other terminals) of the non-volatile storage elements. The programming pulses have 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.

Abstract: 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.

Abstract: In a non-volatile storage system, one or more substrate channel regions for an unselected NAND string are boosted during programming to inhibit program disturb. A voltage applied to one or more unselected word lines associated with at least a first channel region is increased during a program pulse time period in which a program pulse is applied to a selected word line. The increase can be gradual, in the form of a ramp, or step-wise. The boosting level of the first channel region can be maintained. The increase in the voltage applied to the one or more unselected word lines can vary with temperature as well. Before the program pulse time period, the voltage applied to the one or more unselected word lines can be ramped up at a faster rate for a second, adjacent channel region than for the first channel region, to help isolate the channel regions.

Abstract: Program disturb is reduced in a non-volatile storage system by programming storage elements on a selected word line WLn in separate groups, according to the state of their WLn?1 neighbor storage element, and applying an optimal pass voltage to WLn?1 for each group. Initially, the states of the storage elements on WLn?1 are read. A program iteration includes multiple program pulses. A first program pulse is applied to WLn while a first pass voltage is applied to WLn?1, a first group of WLn storage elements is selected for programming, and a second group of WLn storage elements is inhibited. Next, a second program pulse is applied to WLn while a second pass voltage is applied to WLn?1, the second first group of WLn storage elements is selected for programming, and the first group of WLn storage elements is inhibited. A group can include one or more data states.

Abstract: To program a set of non-volatile storage elements, a set of programming pulses are applied to the control gates (or other terminals) of the non-volatile storage elements. The programming pulses have 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.

Abstract: 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.

Abstract: Program disturb is reduced in a non-volatile storage system by programming storage elements on a selected word line WLn in separate groups, according to the state of their WLn?1 neighbor storage element, and applying an optimal pass voltage to WLn?1 for each group. Initially, the states of the storage elements on WLn?1 are read. A program iteration includes multiple program pulses. A first program pulse is applied to WLn while a first pass voltage is applied to WLn?1, a first group of WLn storage elements is selected for programming, and a second group of WLn storage elements is inhibited. Next, a second program pulse is applied to WLn while a second pass voltage is applied to WLn?1, the second first group of WLn storage elements is selected for programming, and the first group of WLn storage elements is inhibited. A group can include one or more data states.

Abstract: 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.

Abstract: In a programming operation, selected storage elements which reach a lockout condition are subject to reduced channel boosting in a program portion of the next program-verify iteration, to reduce coupling effects on the storage elements which continue to be programmed. In subsequent program-verify iterations, the locked out storage elements are subject to full channel boosting. Or, the boosting can be stepped up over multiple program-verify iterations after lockout. The amount of channel boosting can be set by adjusting the timing of a channel pre-charge operation and by stepping up pass voltages which are applied to unselected word lines. The reduced channel boosting can be implemented for a range of program-verify iterations where the lockout condition is most likely to be first reached, for one or more target data states.

Abstract: 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.