Abstract: A trench having a uniform depth is provided in an upper portion of a semiconductor substrate. A continuous dielectric material layer is formed, which includes a gate dielectric that fills an entire volume of the trench. A gate electrode is formed over the gate dielectric such that the gate electrode overlies a center portion of the gate dielectric and does not overlie a first peripheral portion and a second peripheral portion of the gate dielectric that are located on opposing sides of the center portion of the gate dielectric. After formation of a dielectric gate spacer, a source extension region and a drain extension region are formed within the semiconductor substrate by doping respective portions of the semiconductor substrate.

Abstract: A three-dimensional stacked memory device is configured to provide uniform programming speeds of different sets of memory strings formed in memory holes. In a process for removing sacrificial material from word line layers, a block oxide layer in the memory holes is etched away relatively more when the memory hole is relatively closer to an edge of the word line layers where an etchant is introduced. A thinner block oxide layer is associated with a faster programming speed. To compensate, memory strings at the edges of the word line layers are programmed together, separate from the programming of interior memory strings. A program operation can use a higher initial program voltage for programming the interior memory strings compared to the edge memory strings.

Abstract: A memory device includes an alternating stack of insulating layers and electrically conductive layers. Vertical NAND strings are formed through the alternating stack, each of which includes a drain region, memory cell charge storage transistors, and a pair of drain select transistors in a series connection. A common bit line is electrically connected to drain regions of two vertical NAND strings. The drain select transistors of the two vertical NAND strings are configured such that drain select transistors sharing a first common drain select gate electrode provide a higher threshold voltage for one of the two vertical NAND strings, and drain select transistors sharing a second common drain select gate electrode provide a higher threshold voltage for the other of the two vertical NAND strings. The different threshold voltages can be provided by a combination of a masked ion implantation and selective charge injection.

Abstract: A layer stack including an alternating stack of insulating layers and sacrificial material layers is formed over a substrate. After formation of memory stack structures, backside trenches are formed through the layer stack. The sacrificial material layers are replaced with electrically conductive layers. Drain select level dielectric isolation structures are formed through drain select level of the stack after formation of the electrically conductive layers. The drain select level dielectric isolation structures laterally separate portions of conductive layers that are employed as drain select level gate electrodes for the memory stack structures.

Abstract: A three dimensional NAND memory device includes word line driver devices located on or over a substrate, an alternating stack of word lines and insulating layers located over the word line driver devices, a plurality of memory stack structures extending through the alternating stack, each memory stack structure including a memory film and a vertical semiconductor channel, and through-memory-level via structures which electrically couple the word lines in a first memory block to the word line driver devices. The through-memory-level via structures extend through a through-memory-level via region located between a staircase region of the first memory block and a staircase region of another memory block.

Abstract: A three-dimensional memory device including self-aligned drain select level electrodes is provided. Memory stack structures extend through an alternating stack of insulating layers and spacer material layers. Each of the memory stack structures includes a memory film and a memory level channel portion. Drain select level channel portions are formed over the memory level channel portions with respective lateral shifts with respect to underlying memory stack structures. The direction of lateral shifts alternates from row to row for each row of drain select level channel portions. Drain select level gate dielectrics and drain select level gate electrodes are formed on the drain select level channel portions. Each drain select level gate electrode controls two rows of drain select level channel portions, and is laterally spaced from neighboring drain select level gate electrodes.

Abstract: After formation of an alternating stack of insulating layers and sacrificial material layers, a memory opening can be formed through the alternating stack, which is subsequently filled with a columnar semiconductor pedestal portion and a memory stack structure. Breakage of the columnar semiconductor pedestal portion under mechanical stress can be avoided by growing a laterally protruding semiconductor portion by selective deposition of a semiconductor material after removal of the sacrificial material layers to form backside recesses. At least an outer portion of the laterally protruding semiconductor portion can be oxidized to form a tubular semiconductor oxide spacer. Electrically conductive layers can be formed in the backside recesses to provide word lines for a three-dimensional memory device.

Abstract: The contact area between a source strap structure of a buried source layer and semiconductor channels within memory structures can be increased by laterally expanding a source-level volume in which the memory stack structures are formed. In one embodiment, sacrificial semiconductor pedestals can be formed in source-level memory openings prior to formation of a vertically alternating stack of insulating layers and sacrificial material layers. Memory openings can include bulging portions formed by removal of the sacrificial semiconductor pedestals. Memory stack structures can be formed with a greater sidewall surface area in the bulging portions to provide a greater contact area with the source strap structure. Alternatively, bottom portions of memory openings can be expanded selective to upper portions during, or after, formation of the memory openings to provide bulging portions and to increase the contact area with the source strap structure.

Abstract: A linear mark extending perpendicular to a primary step direction of stepped terrace for a three-dimensional memory device can be employed as a reference feature for aligning a trimming material layer before initiating an etch-and-trim process sequence. The linear mark can be formed as a linear trench or a linear rail structure. The distance between a sidewall of each trimming material layer and the linear mark can be measured at multiple locations that are laterally spaced apart perpendicular to the primary step direction to provide statistically significant data points, which can be employed to provide an enhanced control of the staircase patterning process. Likewise, locations of patterned stepped surfaces can be measured at multiple locations to provide enhanced control of the locations of vertical steps in the stepped terrace.

Abstract: A three-dimensional memory device including self-aligned drain select level electrodes is provided. Memory stack structures extend through an alternating stack of insulating layers and spacer material layers. Each of the memory stack structures includes a memory film and a memory level channel portion. Drain select level channel portions are formed over the memory level channel portions with respective lateral shifts with respect to underlying memory stack structures. The direction of lateral shifts alternates from row to row for each row of drain select level channel portions. Drain select level gate dielectrics and drain select level gate electrodes are formed on the drain select level channel portions. Each drain select level gate electrode controls two rows of drain select level channel portions, and is laterally spaced from neighboring drain select level gate electrodes.

Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate and memory stack structures extending through the alternating stack. Each memory stack structure includes a memory film and a vertical semiconductor channel. An isolation trench laterally extends along a horizontal direction and divides at least two topmost electrically conductive layers. Two conductive rail structures are located on lengthwise sidewalls of the isolation trench and are electrically shorted to respective segments of the at least two topmost electrically conductive layers.

Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate and memory stack structures extending through the alternating stack. Each memory stack structure includes a memory film and a vertical semiconductor channel. An isolation trench laterally extends along a horizontal direction and divides at least two topmost electrically conductive layers. Two conductive rail structures are located on lengthwise sidewalls of the isolation trench and are electrically shorted to respective segments of the at least two topmost electrically conductive layers.

Abstract: A three-dimensional memory device including self-aligned drain select level electrodes is provided. Memory stack structures extend through an alternating stack of insulating layers and spacer material layers. Each of the memory stack structures includes a memory film and a memory level channel portion. Drain select level channel portions are formed over the memory level channel portions with respective lateral shifts with respect to underlying memory stack structures. The direction of lateral shifts alternates from row to row for each row of drain select level channel portions. Drain select level gate dielectrics and drain select level gate electrodes are formed on the drain select level channel portions. Each drain select level gate electrode controls two rows of drain select level channel portions, and is laterally spaced from neighboring drain select level gate electrodes.

Abstract: The contact area between a source strap structure of a buried source layer and semiconductor channels within memory structures can be increased by laterally expanding a source-level volume in which the memory stack structures are formed. In one embodiment, sacrificial semiconductor pedestals can be formed in source-level memory openings prior to formation of a vertically alternating stack of insulating layers and sacrificial material layers. Memory openings can include bulging portions formed by removal of the sacrificial semiconductor pedestals. Memory stack structures can be formed with a greater sidewall surface area in the bulging portions to provide a greater contact area with the source strap structure. Alternatively, bottom portions of memory openings can be expanded selective to upper portions during, or after, formation of the memory openings to provide bulging portions and to increase the contact area with the source strap structure.

Abstract: A three-dimensional stacked memory device is configured to provide uniform programming speeds of different sets of memory strings formed in memory holes. In a process for removing sacrificial material from word line layers, a block oxide layer in the memory holes is etched away relatively more when the memory hole is relatively closer to an edge of the word line layers where an etchant is introduced. A thinner block oxide layer is associated with a faster programming speed. To compensate, memory strings at the edges of the word line layers are programmed together, separate from the programming of interior memory strings. A program operation can use a higher initial program voltage for programming the interior memory strings compared to the edge memory strings.

Abstract: A cylindrical confinement electron gas confined within a two-dimensional cylindrical region can be formed in a vertical semiconductor channel extending through a plurality of electrically conductive layers comprising control gate electrodes. A memory film in a memory opening is interposed between the vertical semiconductor channel and the electrically conductive layers. The vertical semiconductor channel includes a wider band gap semiconductor material and a narrow band gap semiconductor material. The cylindrical confinement electron gas is formed at an interface between the wider band gap semiconductor material and the narrow band gap semiconductor material. As a two-dimensional electron gas, the cylindrical confinement electron gas can provide high charge carrier mobility for the vertical semiconductor channel, which can be advantageously employed to provide higher performance for a three-dimensional memory device.

Abstract: A layer stack including an alternating stack of insulating layers and sacrificial material layers is formed over a substrate. After formation of memory stack structures, backside trenches are formed through the layer stack. The sacrificial material layers are replaced with electrically conductive layers. Drain select level dielectric isolation structures are formed through drain select level of the stack after formation of the electrically conductive layers. The drain select level dielectric isolation structures laterally separate portions of conductive layers that are employed as drain select level gate electrodes for the memory stack structures.

Abstract: Memory stack structures can be formed through an alternating stack of insulating layers and spacer material layers that are formed as, or are subsequently replaced with, electrically conductive layers. The memory stack structures can be formed as rows having a first pitch. Additional insulating layers and at least one drain select level dielectric layer are formed over the alternating stack. Drain select level openings are formed in rows having a smaller second pitch. Partial replacement of the at least one drain select level dielectric layer forms spaced apart electrically conductive line structures that surround a respective plurality of drain select level openings. Drain select level channel portions are subsequently formed in respective drain select level openings.

Abstract: A three-dimensional memory device includes an alternating stack of electrically conductive layers and insulating layers located over a substrate, an array of memory stack structures. A source conductive line structure is provided between the substrate and the alternating stack. The source conductive line structure includes a plurality of parallel conductive rail structures extending along a same horizontal direction and adjoined to a common conductive straddling structure. Each memory stack structure straddles a vertical interface between a conductive rail structure and a support matrix. A semiconductor channel in each memory stack structure contacts a respective conductive rail structure and the support matrix.

Abstract: A monolithic three dimensional NAND string includes a plurality of control gate electrodes extending substantially parallel to a major surface of a substrate, a memory opening extending substantially perpendicular to the major surface of the substrate and filled with a memory opening material including a memory film, and a dummy opening extending substantially perpendicular to the major surface of the substrate and filled with a dummy channel material which is different from the memory opening material. The dummy channel material has a higher Young's modulus than the memory opening material to offset warpage of the substrate due to the one of compressive and tensile stress imposed by the plurality of control gate electrodes on the substrate.