Abstract: Methods for improving channel boosting and reducing program disturb during programming of memory cells within a memory array are described. The memory array may comprise a NAND flash memory structure, such as a vertical NAND structure or a bit cost scalable (BiCS) NAND structure. In some cases, by applying continuous voltage ramping to unselected word lines during or throughout a programming operation, the boosting of channels associated with program inhibited memory cells may be improved. In one example, the slope and timing of a Vpass waveform applied to a group of unselected word lines (e.g.

Abstract: Techniques are provided for avoiding over-programming which can occur on memory cells connected to a data word line at a source-side of a block of word lines. A gradient in the channel potential is created during a program voltage between the data word line and an adjacent dummy word line. This gradient generates electron-hole pairs which can contribute to over programming, where the over programming is worse at higher temperatures. In one aspect, pass voltages of unselected word lines are set to be relatively lower when the temperature is relatively higher, and when the selected word line is among a set of one or more source-side word lines. On the other hand, the pass voltages are set to be relatively higher when the temperature is relatively higher, and when the selected word line is not among the one or more source-side word lines.

Abstract: A memory stack structure includes a cavity including a back gate electrode, a back gate dielectric, a semiconductor channel, and at least one charge storage element. In one embodiment, a line trench can be filled with a memory film layer, and a plurality of semiconductor channels can straddle the line trench. The back gate electrode can extend along the lengthwise direction of the line trench. In another embodiment, an isolated memory opening overlying a patterned conductive layer can be filled with a memory film, and the back gate electrode can be formed within a semiconductor channel and on the patterned conductive layer. A dielectric cap portion electrically isolates the back gate electrode from a drain region. The back gate electrode can be employed to bias the semiconductor channel, and to enable sensing of multinary bits corresponding to different amounts of electrical charges stored in a memory cell.

Abstract: A non-volatile storage system includes a plurality of non-volatile storage elements arranged in two dimensional or three dimensional structures. The system applies programming to the non-volatile storage elements and performs verification of the programming. The verification includes performing a multi-strobe sensing operation to test for multiple data states while applying a common word line voltage.

Abstract: A memory device and a method of making a memory device that includes a stack of alternating layers of a first material and a second material different from the first material over a substrate, where the layers of the second material form a plurality of conductive control gate electrodes. A plurality of NAND memory strings extend through the stack, where each NAND memory string includes a semiconductor channel which contains at least a first portion which extends substantially perpendicular to a major surface of the substrate and at least one memory film located between the semiconductor channel and the plurality of conductive control gate electrodes. A source line including a metal silicide material extends through the stack.

Abstract: Techniques for reading data from memory cells arranged along a common charge trapping layer. One example is in a 3D stacked non-volatile memory device. Memory cells on a word line layer WLLn can be disturbed by programming of memory cells on an adjacent word line layer WLLn+1, resulting in uncorrectable errors. The memory cells on WLLn are read in a data recovery read operation which applies an elevated pass voltage to WLLn+1. The elevated pass voltage decreases and narrows the threshold voltages on WLLn, which facilitates reading. The data recovery read operation compensates for the lower threshold voltages of the cells by lowering the control gate voltage, raising the source voltage or adjusting a sensing period, demarcation level or pre-charge level in sensing circuitry. The elevated pass voltage can be stepped up in repeated read attempts until there are no uncorrectable errors or a limit is reached.

Abstract: A memory stack structure can be formed through a stack of an alternating plurality of first material layers and second material layers and through an overlying temporary material layer having a different composition than the first and second material layers. The memory stack structure can include a memory film and a semiconductor channel layer. The overlying temporary material layer is removed selective to the stack to form a lateral recess. Portions of the memory film are removed around the lateral recess, and dopants are laterally introduced into an upper portion of the semiconductor channel to form a self-aligned drain region.

Abstract: Methods for improving channel boosting and reducing program disturb during programming of memory cells within a memory array are described. The memory array may comprise a NAND flash memory structure, such as a vertical NAND structure or a bit cost scalable (BiCS) NAND structure. In some cases, by applying continuous voltage ramping to unselected word lines during or throughout a programming operation, the boosting of channels associated with program inhibited memory cells may be improved. In one example, the slope and timing of a Vpass waveform applied to a group of unselected word lines (e.g., the neighboring word lines of the selected word line) during the programming operation may be set based on the location of the selected word line within the memory array and the locations of the group of unselected word lines within the memory array.

Abstract: A memory stack structure for a three-dimensional device includes an alternating stack of insulator layers and spacer material layers. A memory opening is formed through the alternating stack. A memory material layer, a tunneling dielectric layer, and a silicon oxide liner are formed in the memory opening. A sacrificial liner is subsequently formed over the tunneling dielectric layer. The layer stack is anisotropically etched to physically expose a semiconductor surface of the substrate underneath the memory opening. The sacrificial liner may be removed prior to, or after, the anisotropic etch. The silicon oxide liner is removed after the anisotropic etch. A semiconductor channel layer can be deposited directly on the tunneling dielectric layer as a single material layer without any interface therein.

Abstract: A NAND memory cell region of a NAND device includes a conductive source line that extends substantially parallel to a major surface of a substrate, a first semiconductor channel that extends substantially perpendicular to a major surface of the substrate, and a second semiconductor channel that extends substantially perpendicular to the major surface of the substrate. At least one of a bottom portion and a side portion of the first semiconductor channel contacts the conductive source line and at least one of a bottom portion and a side portion of the second semiconductor channel contacts the conductive source line.

Abstract: Read disturb due to hot electron injection is reduced in a 3D memory device by controlling the magnitude and timing of word line and select gate ramp down voltages at the end of a sensing operation. In an example read operation, a predefined subset of word lines includes source-side and drain-side word lines. For the predefined subset of word lines, word line voltages are ramped down before the voltages of the select gates are ramped down. Subsequently, for a remaining subset of word lines, word line voltages are ramped down, but no later than the ramping down of the voltages of the select gates. The timing of the ramp down of the selected word line depends on whether it is among the predefined subset or the remaining subset. The predefined subset can include a number of adjacent or non-adjacent word lines.

Abstract: Techniques for forming 3D memory arrays are disclosed. Memory openings are filled with a sacrificial material, such as silicon or nitride. Afterwards, a replacement technique is used to remove nitride from an ONON stack and replace it with a conductive material such as tungsten. Afterwards, memory cell films are formed in the memory openings. The conductive material serves as control gates of the memory cells. The control gate will not suffer from corner rounding. ONON shrinkage is avoided, which will prevent control gate shrinkage. Block oxide between the charge storage region and control gate may be deposited after control gate replacement, so the uniformity is good. Block oxide may be deposited after control gate replacement, so TiN adjacent to control gates can be thicker to prevent fluorine attacking the insulator between adjacent control gates. Therefore, control gate to control gate shorting is prevented.

Abstract: Fabrication techniques for a three-dimensional stack memory device remove the charge-trapping material from the select gate transistors and the dummy memory cells to avoid unintentional programming which increases the threshold voltage. In one approach, a stack is formed with a sacrificial material for the a) control gate layers of the select gate transistors and the dummy memory cells and the b) control gate layers of the data memory cells. A slit is formed to allow etchants to be introduced to selectively remove the sacrificial material and then the charge-trapping material for the select gate transistors and dummy memory cells. A protective layer is provided partway in the slit, or the slit is etched in two steps.

Abstract: Fabrication techniques for a three-dimensional stack memory device remove the charge-trapping material from the select gate transistors and the dummy memory cells to avoid unintentional programming which increases the threshold voltage. In one approach, a stack is formed with a sacrificial material for the a) control gate layers of the select gate transistors and the dummy memory cells and the b) control gate layers of the data memory cells. A slit is formed to allow etchants to be introduced to selectively remove the sacrificial material and then the charge-trapping material for the select gate transistors and dummy memory cells. A protective layer is provided partway in the slit, or the slit is etched in two steps.

Abstract: Techniques are provided for programming a three-dimensional memory device while minimizing over-programming and program disturb. When a selected word line is at the source-side of a set of word lines, a channel gradient is created in the channel adjacent to the selected word line when a program voltage is applied. The gradient generates hot carriers which can cause over-programming of memory cells connected to the selected word line. To reduce the amount of hot carriers, a ramp rate and/or duration of a first step up of the program voltage is reduced. When the selected word line is not at the source-side of the set of word lines, a baseline ramp rate and/or duration can be used. A ramp rate and/or duration of the voltage applied to unselected word lines can be reduced as well but by a lesser amount.

Abstract: A non-volatile memory system that has two or more sub-blocks in a block performs a check before accessing memory cells to see if the condition of a sub-block that is not being accessed could affect the memory cells being accessed. If such a sub-block is found then parameters used to access the cells may be modified according to a predetermined scheme.

Abstract: Techniques are provided for reducing program disturb in a 3D memory device. The techniques include compensating for a temperature dependence of program disturb. The techniques may include compensating for how program disturb depends on the location of the word line that is selected for programming. In one aspect, the voltage that is applied to the control gates drain side select transistors of unselected NAND strings is adjusted during programming based on temperature. Greater temperature compensation may be applied when the selected word line is closer to the drain side select transistors.

Abstract: Techniques are provided for programming a memory device. A pre-charge phase is used to boost the channel of an unselected NAND string by allowing a bit line voltage to reach the channel. To maximize the channel pre-charge while also minimizing program disturb, a drain-side dummy word line voltage is controlled based on the position of the selected word line. The drain-side dummy word line voltage can be relatively high or low when the selected word line is relatively far from or close to the drain-side dummy word line, respectively. When the drain-side dummy word line voltage is relatively high, the bit line voltage can easily pass through and boost the channel. When the drain-side dummy word line voltage is relatively low, program disturb of drain-side data word lines is reduced due to a smaller channel gradient and a corresponding reduced amount of hot carriers.

Abstract: A NAND memory cell region of a NAND device includes a conductive source line that extends substantially parallel to a major surface of a substrate, a first semiconductor channel that extends substantially perpendicular to a major surface of the substrate, and a second semiconductor channel that extends substantially perpendicular to the major surface of the substrate. At least one of a bottom portion and a side portion of the first semiconductor channel contacts the conductive source line and at least one of a bottom portion and a side portion of the second semiconductor channel contacts the conductive source line.

Abstract: Techniques are provided for reducing program disturb in a 3D memory device. The techniques include compensating for a temperature dependence of program disturb. The techniques may include compensating for how program disturb depends on the location of the word line that is selected for programming. In one aspect, the voltage that is applied to the control gates drain side select transistors of unselected NAND strings is adjusted during programming based on temperature. Greater temperature compensation may be applied when the selected word line is closer to the drain side select transistors.