Abstract: A 3D NAND memory has vertical NAND strings across multiple memory planes above a substrate, with each memory cell of a NAND string residing in a different memory layer. Word lines in each memory plane each has a series of socket components aligned to embed respective floating gates of a group memory cells. In this way, the word line to floating gate capacitive coupling is enhanced thereby allowing a 4 to 8 times reduction in cell dimension as well as reducing floating-gate perturbations between neighboring cells. In one embodiment, each NAND string has source and drain switches that each employs an elongated polysilicon gate with metal strapping to enhance switching. The memory is fabricated by an open-trench process on a multi-layer slab that creates lateral grottoes for forming the socket components.

Abstract: A non-volatile memory system including multi-level storage optimized for ramp sensing and soft decoding is provided. Sensing is performed at a higher bit resolution than an original user data encoding to improve the accuracy of reading state information from non-volatile storage elements. Higher resolution state information is used for decoding the original user data to improve read performance through improved error handling. Ramp sensing is utilized to determine state information by applying a continuous input scanning sense voltage that spans a range of read compare points. Full sequence programming is enabled as is interleaved coding of the user data over all of the data bit sets associated with the storage elements.

Abstract: A non-volatile memory has an ADC that digitizes an analog voltage in a range delimited by V1 and V2 into N intervals, resulting in a digital Vx with x between 1 to N. A ramp voltage Vramp(x) calibrated to rise linearly from V1 to V2 in x=1 to N clock cycles is used to scan the analog voltage. Vx is then given by Vx=Vramp(x). The ramp voltage is provided by a constant current charging a capacitor and has a slope proportional to a DAC resistor, R(x) that is programmable from 1 to N. In a calibration mode, the R(x) is set to N, which results in K clock cycles spanning V1 to V2. In a subsequent normal mode, the DAC resistor is reset to R(K) to result in a calibrated ramp voltage that would rise from V1 to V2 in N clock cycles.

Abstract: A non-volatile memory system including multi-level storage optimized for ramp sensing and soft decoding is provided. Sensing is performed at a higher bit resolution than an original user data encoding to improve the accuracy of reading state information from non-volatile storage elements. Higher resolution state information is used for decoding the original user data to improve read performance through improved error handling. Ramp sensing is utilized to determine state information by applying a continuous input scanning sense voltage that spans a range of read compare points. Full sequence programming is enabled as is interleaved coding of the user data over all of the data bit sets associated with the storage elements.

Abstract: A 3D NAND memory has vertical NAND strings across multiple memory layers above a substrate, with each memory cell of a NAND string residing in a different memory layer. Word lines in each memory layer each has a series of socket components aligned to embed respective floating gates of a group memory cells. In this way, the word line to floating gate capacitive coupling is enhanced thereby allowing a 4 to 8 times reduction in cell dimension as well as reducing floating-gate perturbations between neighboring cells. At the same time floating-gate to floating-gate crosstalk is reduced. The memory is fabricated by using odd and even subarrays of vertical shafts on a multi-layer slab to create at different times odd and even socket components that overlap to form continuous word lines with socket components. A self-aligned 4-masks process is employed on the multi-layer slab.

Abstract: A non-volatile memory has an ADC that digitizes an analog voltage in a range delimited by V1 and V2 into N intervals, resulting in a digital Vx with x between 1 to N. A ramp voltage Vramp(x) calibrated to rise linearly from V1 to V2 in x=1 to N clock cycles is used to scan the analog voltage. Vx is then given by Vx=Vramp(x). The ramp voltage is provided by a constant current charging a capacitor and has a slope proportional to a DAC resistor, R(x) that is programmable from 1 to N. In a calibration mode, the R(x) is set to N, which results in K clock cycles spanning V1 to V2. In a subsequent normal mode, the DAC resistor is reset to R(K) to result in a calibrated ramp voltage that would rise from V1 to V2 in N clock cycles.

Abstract: A 3D NAND memory has vertical NAND strings across multiple memory planes above a substrate, with each memory cell of a NAND string residing in a different memory layer. Word lines in each memory plane each has a series of socket components aligned to embed respective floating gates of a group memory cells. In this way, the word line to floating gate capacitive coupling is enhanced thereby allowing a 4 to 8 times reduction in cell dimension as well as reducing floating-gate perturbations between neighboring cells. In one embodiment, each NAND string has source and drain switches that each employs an elongated polysilicon gate with metal strapping to enhance switching. The memory is fabricated by an open-trench process on a multi-layer slab that creates lateral grottoes for forming the socket components.

Abstract: A 3D NAND memory has vertical NAND strings across multiple memory planes above a substrate, with each memory cell of a NAND string residing in a different memory layer. Word lines in each memory plane each has a series of socket components aligned to embed respective floating gates of a group memory cells. In this way, the word line to floating gate capacitive coupling is enhanced thereby allowing a 4 to 8 times reduction in cell dimension as well as reducing floating-gate perturbations between neighboring cells. In one embodiment, each NAND string has source and drain switches that each employs an elongated polysilicon gate with metal strapping to enhance switching. The memory is fabricated by an open-trench process on a multi-layer slab that creates lateral grottoes for forming the socket components.

Abstract: In a 3D memory with vertical local bit lines, each local bit line is switchably connected to a node on a global bit line having first and second ends, the local bit line voltage is maintained at a predetermined reference level in spite of being driven by a bit line driver from a first end of the global bit line that constitutes variable circuit path length and circuit serial resistance. This is accomplished by a feedback voltage regulator comprising a voltage clamp at the first end of the global bit line controlled by a bit line voltage comparator at the second end of the global bit line. The comparator compares the bit line voltage sensed from the second end with the predetermined reference level and outputs a control voltage to control the voltage clamp In this way the voltage at the local bit line is regulated at the reference voltage.

Abstract: A 3D NAND memory has vertical NAND strings across multiple memory planes above a substrate, with each memory cell of a NAND string residing in a different memory layer. Word lines in each memory plane each has a series of socket components aligned to embed respective floating gates of a group memory cells. In this way, the word line to floating gate capacitive coupling is enhanced thereby allowing a 4 to 8 times reduction in cell dimension as well as reducing floating-gate perturbations between neighboring cells. In one embodiment, each NAND string has source and drain switches that each employs an elongated polysilicon gate with metal strapping to enhance switching. The memory is fabricated by an open-trench process on a multi-layer slab that creates lateral grottoes for forming the socket components.

Abstract: A non-volatile memory device capable of reading and writing a large number of memory cells with multiple read/write circuits in parallel has an architecture that reduces redundancy in the multiple read/write circuits to a minimum. The multiple read/write circuits are organized into a bank of similar stacks of components. In one aspect, each stack of components has individual components factorizing out their common subcomponents that do not require parallel usage and sharing them as a common component serially. Other aspects, include serial bus communication between the different components, compact I/O enabled data latches associated with the multiple read/write circuits, and an architecture that allows reading and programming of a contiguous row of memory cells or a segment thereof. The various aspects combined to achieve high performance, high accuracy and high compactness.

Abstract: In a 3D nonvolatile memory with memory elements arranged in a three-dimensional pattern defined by rectangular coordinates having x, y and z-directions and with a plurality of parallel planes from a bottom plane to a top plane stacked in the z-direction over a semiconductor substrate; a plurality of local bit lines elongated in the z-direction through the plurality of layers and arranged in a two-dimensional rectangular array of bit line pillars having rows in the x-direction and columns in the y-direction; the 3D nonvolatile memory further having a plurality of staircase word lines spaced apart in the y-direction and between and separated from the plurality of bit line pillars at a plurality of crossings, individual staircase word lines each having a series of alternating steps and risers elongated respectively in the x-direction and z-direction traversing across the plurality of planes in the z-direction with a segment in each plane.

Abstract: The selected bit line in a non-volatile memory carries a cell conduction current to be measured and also a leakage current or noise due to weak coupling with neighboring array structures. In a first phase, a sense amplifier senses the bit line current by discharging a capacitor with the combined current (cell conduction current plus the leakage current) over a predetermined time. In a second phase, the cell conduction current is minimized and significantly the leakage current in the selected bit line is used to recharge in tandem the capacitor in a time same as the predetermined time, effectively subtracting the component of the leakage current measured in the first sensing phase. The resultant voltage drop on the capacitor over the two sensing phases provides a measure of the cell conduction current alone, thereby avoiding reading errors due to the leakage current present in the selected bit line.

Abstract: A 3D array of nonvolatile memory has each read/write element accessed at a crossing between a word line and a bit line. The read/write element forms a tubular electrode having an outside shell of R/W material enclosing an oxide core. In a rectangular form, one side of the electrode contacts the word line and another side contacts the bit line. The thickness of the shell rather than its surface areas in contact with the word line and bit line determines the conduction cross-section and therefore the resistance. By adjusting the thickness of the shell, independent of its contact area with either the word line or bit line, each read/write element can operate with a much increased resistance and therefore much reduced current. Processes to manufacture a 3D array with such tubular R/W elements 3D array are also described.

Abstract: A three-dimensional array adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes.

Abstract: A non-volatile memory device capable of reading and writing a large number of memory cells with multiple read/write circuits in parallel has an architecture that reduces redundancy in the multiple read/write circuits to a minimum. The multiple read/write circuits are organized into a bank of similar stacks of components. In one aspect, each stack of components has individual components factorizing out their common subcomponents that do not require parallel usage and sharing them as a common component serially. Other aspects, include serial bus communication between the different components, compact I/O enabled data latches associated with the multiple read/write circuits, and an architecture that allows reading and programming of a contiguous row of memory cells or a segment thereof. The various aspects combined to achieve high performance, high accuracy and high compactness.

Abstract: A 3D memory with vertical local bit lines global bit lines has an in-line vertical switch in the form of a thin film transistor (TFT) formed as a vertical structure, to switch a local bit line to a global bit line. The TFT is implemented to switch a maximum of current carried by the local bit line by a strongly coupled select gate which must be fitted within the space around the local bit line. Maximum thickness of the select gate is implemented with the select gate exclusively occupying the space along the x-direction from both sides of the local bit line. The switches for odd and even bit lines of the row are staggered and offset in the z-direction so that the select gates of even and odd local bit lines are not coincident along the x-direction. The switching is further enhanced with a wrap-around select gate.

Abstract: The selected bit line in a non-volatile memory carries a cell conduction current to be measured and also a leakage current or noise due to weak coupling with neighboring array structures. In a first phase, a sense amplifier senses the bit line current by discharging a capacitor with the combined current (cell conduction current plus the leakage current) over a predetermined time. In a second phase, the cell conduction current is minimized and significantly the leakage current in the selected bit line is used to recharge in tandem the capacitor in a time same as the predetermined time, effectively subtracting the component of the leakage current measured in the first sensing phase. The resultant voltage drop on the capacitor over the two sensing phases provides a measure of the cell conduction current alone, thereby avoiding reading errors due to the leakage current present in the selected bit line.

Abstract: A 3D nonvolatile memory has memory elements arranged in a three-dimensional pattern defined by rectangular coordinates having x, y and z-directions and with a plurality of parallel planes stacked in the z-direction over a semiconductor substrate. It has vertical local bit lines and a plurality of staircase word lines. Each staircase word line has a series of alternating segments and risers elongated respectively in the x-direction and z-direction traversing across the plurality of planes in the z-direction with a segment in each plane. Methods of forming a slab of multi-plane memory with staircase word lines include processes with one masking and with two maskings for forming each plane.

Abstract: A non-volatile memory device capable of reading and writing a large number of memory cells with multiple read/write circuits in parallel has an architecture that reduces redundancy in the multiple read/write circuits to a minimum. The multiple read/write circuits are organized into a bank of similar stacks of components. Redundant circuits such as a processor for processing data among stacks each associated with multiple memory cells are factored out. The processor is implemented with an input logic, a latch and an output logic. The input logic can transform the data received from either the sense amplifier or the data latches. The output logic further processes the transformed data to send to either the sense amplifier or the data latches or to a controller. This provides an infrastructure with maximum versatility and a minimum of components for sophisticated processing of the data sensed and the data to be input or output.