Abstract: A method (of forming a semiconductor device) including forming cell regions (in alternating first and second rows having first and second heights) including forming a majority of the cell regions in the first rows including: limiting a height of the majority of the cell regions to be single-row cell regions that span corresponding single one of the first rows but do not extend therebeyond; and forming a minority of the cell regions correspondingly in at least the first rows including reducing widths of the multi-row cell regions to be smaller than comparable single-row cell regions; and expanding heights of the minority of the cell regions to be multi-row cell regions, each of the multi-row cell regions spanning a corresponding single first row and at least a corresponding second row such that cell region densities of the second rows are at least about forty percent.

Abstract: A semiconductor device according to an embodiment includes a stacked body having first films and second films that are alternately stacked, a light shielding film provided in a specific layer of the stacked body and having a higher optical absorptivity than that of the second films, and a channel film extending in the stacked body in the stacking direction. The channel film includes a first part located on an upper side than the light shielding film in the stacking direction and containing a monocrystalline semiconductor.

Abstract: A MOSFET device and method of making, the device including a floating gate layer formed within a trench in a substrate, a tunnel dielectric layer located on sidewalls and a bottom of the trench, a control gate dielectric layer located on a top surface of the floating gate layer, a control gate layer located on a top surface of the control gate dielectric layer and sidewall spacers located on sidewalls of the control gate dielectric layer and the control gate layer.

Abstract: Embodiments of through array contact structures of a 3D memory device is disclosed. The 3D NAND memory device includes an alternating layer stack disposed on a substrate. The alternating layer stack includes a first region including an alternating dielectric stack, and a second region including an alternating conductor/dielectric stack. The memory device further comprises a barrier structure extending vertically through the alternating layer stack to laterally separate the first region from the second region, and multiple through array contacts in the first region each extending vertically through the alternating dielectric stack. At least one through array contact is electrically connected with a peripheral circuit.

Abstract: An embodiment of a semiconductor memory device including a multi-layer charge storing layer and methods of forming the same are described. Generally, the device includes a channel formed from a semiconducting material overlying a surface on a substrate connecting a source and a drain of the memory device; a tunnel oxide layer overlying the channel; and a multi-layer charge storing layer including an oxygen-rich, first oxynitride layer on the tunnel oxide layer in which a stoichiometric composition of the first oxynitride layer results in it being substantially trap free, and an oxygen-lean, second oxynitride layer on the first oxynitride layer in which a stoichiometric composition of the second oxynitride layer results in it being trap dense. In one embodiment, the device comprises a non-planar transistor including a gate having multiple surfaces abutting the channel, and the gate comprises the tunnel oxide layer and the multi-layer charge storing layer.

Abstract: A discrete three-dimensional (3-D) processor comprises communicatively coupled first and second dice. The first die comprises 3-D memory (3D-M) arrays, whereas the second die comprises at least a non-memory circuit and at least an off-die peripheral-circuit component of the 3D-M arrays. The first die does not comprise said off-die peripheral-circuit component. The non-memory circuit on the second die is not part of a memory.

Abstract: Some embodiments include apparatuses and methods of operating such apparatuses. One of such apparatuses includes a data line, a conductive region, and a memory cell including a first transistor and a second transistor. The first transistor includes a first channel region coupled to the data line and the conductive region, a charge storage structure, and a first gate. The second transistor includes a second channel region coupled to the data line and the charge storage structure, and a second gate. The first gate is electrically separated from the second gate and opposite from the second gate in a direction from the first channel region to the second channel region.

Abstract: A semiconductor device includes gate layers stacked on a substrate in a first direction perpendicular to an upper surface of the substrate, and channel structures penetrating the gate layers and extending in the first direction, each of the channel structures includes first dielectric layers on side surfaces of the gate layers, respectively, and spaced apart from each other in the first direction, electric charge storage layers on side surfaces of the first dielectric layers, respectively, and spaced apart from each other in the first direction, a second dielectric layer extending perpendicularly to the substrate to conform to side surfaces of the electric change storage layers, and a channel layer extending perpendicularly, and each of the first dielectric layers has a first maximum length, and each of the electric charge storage layers has a second maximum length greater than the first maximum length in the first direction.

Abstract: A microelectronic device comprises a stack structure, at least one staircase structure, contact structures, and support structures. The stack structure comprises vertically alternating conductive structures and insulating structures arranged in tiers, each of the tiers individually comprising one of the conductive structures and one of the insulating structures. The at least one staircase structure is within the stack structure and has steps comprising edges of at least some of the tiers. The contact structures are on the steps of the at least one staircase structure. The support structures horizontally alternate with the contact structures in a first horizontal direction and vertically extend through the stack structure. The support structures have oblong horizontal cross-sectional shapes. Additional microelectronic devices, memory devices, and electronic systems are also described.

Abstract: A semiconductor structure includes a memory array, a staircase unit, conductive bridge structures, a word line driver and conductive routings. The memory array is disposed in an array region of the semiconductor structure and includes word lines. The staircase unit is disposed in a staircase region and surrounded by the array region. The staircase unit includes first and second staircase steps extending from the word lines of the memory array. The first staircase steps and the second staircase steps face towards each other. The conductive bridge structures are electrically connecting the first staircase steps to the second staircase step. The word line driver is disposed below the memory array and the staircase unit, wherein a central portion of the word line driver is overlapped with a central portion of the staircase unit. The conductive routings extend from the first and the second staircase steps to the word line driver.

Abstract: Embodiments of structure and methods for forming a three-dimensional (3D) memory device are provided. In an example, a method for forming a 3D memory device includes forming a bottom select structure extending along a vertical direction through a bottom conductor layer over a substrate and along a horizontal direction to divide the bottom conductor layer into a pair of bottom select conductor layers, forming a plurality of conductor layers and a plurality of insulating layers interleaved on the pair of bottom select conductor layers and the bottom select structure, and forming a plurality of channel structures extending along the vertical direction through the pair of bottom select conductor layers, the plurality of conductor layers, and the plurality of insulating layers and into the substrate.

Abstract: Methods and apparatuses for slit oxide and via formation techniques are described, for example, for fabricating three dimensional memory devices that may include multiple decks of memory cells that each include memory cell stacks and associated access lines. The techniques may create an interconnect region without removing a portion of the memory cell stacks. The interconnect region may include one or more conductive vias extending through the decks of memory cells to couple the access lines with logic circuitry that may be located underneath the decks of memory cells. Further, the techniques may divide an array of memory cells into multiple subarrays of memory cells by forming trenches, which may sever the access lines. In some cases, each subarray of memory cells may be electrically isolated from other subarrays of memory cells. The techniques may reduce a total number of fabrication process steps.

Abstract: A semiconductor memory device according to an embodiment comprises: a semiconductor substrate; a stacked body having a plurality of first insulating layers and conductive layers stacked alternately on the semiconductor substrate; a columnar semiconductor layer contacting the semiconductor substrate in the stacked body being provided extending in a stacking direction of the stacked body and including a first portion and a second portion which is provided above the first portion; a memory layer provided on a side surface of the columnar semiconductor layer facing the stacked conductive layers and extending along the columnar semiconductor layer; and a second insulating layer provided between one of the first insulating layer and the conductive layers of the stacked body.

Abstract: A semiconductor device includes a first conductive structure extending along a vertical direction and a second conductive structure extending along the vertical direction. The second conductive structure is spaced apart from the first conductive structure along a first lateral direction. The semiconductor device includes third conductive structures each extending along the first lateral direction. The third conductive structures are disposed across the first and second conductive structures. The semiconductor device includes a first semiconductor channel extending along the vertical direction. The first semiconductor channel is disposed between the third conductive structures and the first conductive structure, and between the third conductive structures and the second conductive structure. The first and second conductive structures each have a first varying width along the first lateral direction, and the first semiconductor channel has a second varying width along a second lateral direction.

Abstract: Memory device includes a bottom-select-gate (BSG) structure. Cut slits are formed vertically through the BSG structure, on a substrate. A cell-layers structure is formed on the BSG structure. Gate-line slits are formed vertically through the cell-layers structure and the BSG structure, into the substrate and arranged along a first lateral direction to distinguish finger regions. The gate-line slits include a first gate-line slit between first and second finger regions, the first gate-line slit including gate-line sub-slits. The cut slits include a first cut-slit, formed in the second finger region and connecting to a gate-line sub-slit to define a BSG in a first portion of the second finger region. The BSG in the first portion of the second finger region is electrically connected to cell strings in the first finger region through an inter portion between the one gate-line sub-slit and an adjacent gate-line sub-slit.

Abstract: A semiconductor memory device includes a word line extending in a vertical direction on a substrate, a channel layer surrounding the word line to configure a cell transistor and having a horizontal ring shape with a predetermined horizontal width, a bit line disposed at one end of the channel layer in a first horizontal direction and extending in a second horizontal direction perpendicular to the first horizontal direction, and a cell capacitor disposed at other end of the channel layer in the first horizontal direction, the cell capacitor including an upper electrode layer extending in the vertical direction, a lower electrode layer surrounding the upper electrode layer, and a capacitor dielectric layer disposed between the upper electrode layer and the lower electrode layer.

Abstract: Provided is a nonvolatile memory device including a lower electrode on a substrate, an upper electrode on the lower electrode, a tunnel barrier pattern between the lower electrode and the upper electrode, and a fixed charge pattern in contact with the lower electrode and spaced apart from the tunnel barrier pattern with the lower electrode therebetween. The tunnel barrier pattern includes an anti-ferroelectric material. The lower electrode includes a first material. The upper electrode includes a second material. The first material and the second material have different work functions.

Abstract: The semiconductor storage device of an embodiment includes a first conductive layer, a stack disposed above the first conductive layer and including a plurality of second conductive layers in a first direction, and a columnar body that extends in the first direction through the stack, and includes a semiconductor layer and a charge storage film provided between the plurality of conductive layers and the semiconductor layer. A first conductive layer out of the plurality of conductive layers is connected to the semiconductor layer, and the semiconductor layer includes a first region in which a concentration of an n-type impurity is higher than a concentration of a p-type impurity, a second region in which a concentration of a p-type impurity is higher than a concentration of an n-type impurity, and a third region contacted to the first conductive layer and disposed closer to the first region than the second region in the first direction.

Abstract: A semiconductor memory device and a method for fabricating a semiconductor memory device, the device including a peripheral logic structure on a substrate; a horizontal conductive substrate on the peripheral logic structure; a stacked structure including a plurality of electrode pads stacked in a vertical direction; a plate contact plug connected to the horizontal conductive substrate; and a first penetration electrode connected to the lower connection wiring body, wherein upper surfaces of the plate contact plug and the first penetration electrode are on a same plane, the plate contact plug includes an upper part and a lower part directly connected to each other, the first penetration electrode includes an upper part and a lower part directly connected to each other, moving away from upper surfaces of the first penetration electrode and the plate contact plug, widths of the upper parts increase and widths of the lower parts decrease.

Abstract: A method of fabricating an electronic device including a semiconductor memory includes forming a first conductive structure extending in a first direction and having a closed-loop shape, forming a second conductive structure extending in a second direction and having a closed-loop shape, the second direction intersecting the first direction, forming a memory cell located at an intersection of the first conductive structure and the second conductive structure, forming first conductive patterns extending in the first direction by etching an end portion of the first conductive structure, forming second conductive patterns extending in the second direction by etching an end portion of the second conductive structure, forming a first protective layer on an etched surface of each of the first conductive patterns and the second conductive patterns, and forming a gap-fill layer on the first protective layer.

Abstract: Three-dimensional (3D) NAND memory devices and methods are provided. In one aspect, a fabrication method includes depositing a cover layer over a substrate, depositing a sacrificial layer over the cover layer, depositing a layer stack over the sacrificial layer, forming a channel layer extending through the layer stack and the sacrificial layer, performing a first epitaxial growth to deposit a first epitaxial layer on a side portion of the channel layer that is close to the substrate, removing the cover layer, and performing a second epitaxial growth to simultaneously thicken the first epitaxial layer and deposit a second epitaxial layer on the substrate. The layer stack includes first stack layers and second stack layers that are alternately stacked.

Abstract: Embodiments of three-dimensional (3D) memory devices having through stair contacts (TSCs) and methods for forming the same are disclosed. In an example, a 3D memory device includes a memory stack and a TSC. The memory stack includes a plurality of interleaved conductive layers and dielectric layers. Edges of the interleaved conductive layers and dielectric layers define a staircase structure on a side of the memory stack. The TSC extends vertically through the staircase structure of the memory stack. The TSC includes a conductor layer and a spacer circumscribing the conductor layer.

Abstract: A memory cell includes patterning a first trench extending through a first conductive line, depositing a memory film along sidewalls and a bottom surface of the first trench, depositing a channel layer over the memory film, the channel layer extending along the sidewalls and the bottom surface of the first trench, depositing a first dielectric layer over and contacting the channel layer to fill the first trench, patterning a first opening, wherein patterning the first opening comprises etching the first dielectric layer, depositing a gate dielectric layer in the first opening, and depositing a gate electrode over the gate dielectric layer and in the first opening, the gate electrode being surrounded by the gate dielectric layer.

Abstract: Some embodiments include a memory array having a vertical stack of alternating insulative levels and control gate levels. Channel material extends vertically along the stack. The control gate levels comprising conductive regions. The conductive regions include at least three different materials. Charge-storage regions are adjacent the control gate levels. Charge-blocking regions are between the charge-storage regions and the conductive regions.

Abstract: A method of controlling the forming voltage of a dielectric film in a resistive random access memory (ReRAM) device. The method includes depositing a dielectric film contains intrinsic defects on a substrate, forming a plasma-excited treatment gas containing H2 gas, and exposing the dielectric film to the plasma-excited treatment gas to create additional defects in the dielectric film without substantially changing a physical thickness of the dielectric film, where the additional defects lower the forming voltage needed for generating an electrically conducting filament across the dielectric film. The dielectric film can include a metal oxide film and the plasma-excited treatment gas may be formed using a microwave plasma source.

Abstract: According to at least one embodiment, a semiconductor device includes a plurality of insulating films adjacent to each other. A conductive film is provided between the plurality of insulating films. The conductive film includes molybdenum having a grain diameter substantially the same as a distance from an upper surface to a lower surface of the conductive film.

Abstract: In certain aspects, a three-dimensional (3D) memory device includes a memory stack including interleaved conductive layers and dielectric layers, a plurality of channel structures each extending vertically through the memory stack, a conductive layer in contact with source ends of the plurality of channel structures, a first source contact electrically connected to the channel structures, and a second source contact electrically connected to the channel structures.

Abstract: A semiconductor die comprises a device portion comprising: an array of active memory devices extending in a first direction, and interface portions located adjacent to axial ends of the device portion in the first direction. The interface portions have a staircase profile in a vertical direction and comprise an array of dummy memory devices and an array of gate vias. The dummy memory devices are axially aligned with the active memory devices in the first direction, each dummy memory device comprising at least one interface via. Moreover, each row of the array of gate vias extends in the first direction and is located parallel to a row of the array of dummy memory devices in a second direction perpendicular to the first direction. Each gate via is electrically coupled to the at least one interface via of a dummy memory device located adjacent thereto.

Abstract: A semiconductor device includes a substrate and a metallization layer. The substrate has an active region that includes opposite first and second edges. The metallization layer is disposed above the substrate, and includes a pair of metal lines and a metal plate. The metal lines extend from an outer periphery of the active region into the active region and toward the second edge of the active region. The metal plate interconnects the metal lines and at least a portion of which is disposed at the outer periphery of the active region.

Abstract: A semiconductor device includes: an alternating stack that is disposed over a lower structure and includes gate electrodes and dielectric layers which are staked alternately; a memory stack structure that includes a channel layer extending to penetrate through the alternating stack, and a memory layer surrounding the channel layer; a source contact layer in contact with a lower outer wall of the vertical channel layer and disposed between the lower structure and the alternating stack; a source contact plug spaced apart from the memory stack structure and extending to penetrate through the alternating stack; and a sealing spacer suitable for sealing the gate electrodes and disposed between the source contact plug and the gate electrodes. The sealing spacer has an etch resistance that is different from an etch resistance of the dielectric layers.

Abstract: A semiconductor structure is provided. The semiconductor structure includes a staircase structure including a first stair layer and a second stair layer on the first stair layer. The first stair layer comprises a first conductive film. The semiconductor structure includes a landing pad disposed on the first conductive film. The landing pad has a first pad sidewall facing toward the second stair layer, a first lateral gap distance between an upper portion of the first pad sidewall and the second stair layer is smaller than a second lateral gap distance between a lower portion of the first pad sidewall and the second stair layer.

Abstract: Some embodiments include apparatuses and methods of forming the apparatuses.

Abstract: A method used in forming a memory array comprising strings of memory cells comprises forming a stack comprising vertically-alternating insulative tiers and wordline tiers. First charge-blocking material is formed to extend elevationally along the vertically-alternating tiers. The first charge-blocking material has k of at least 7.0 and comprises a metal oxide. A second charge-blocking material is formed laterally inward of the first charge-blocking material. The second charge-blocking material has k less than 7.0. Storage material is formed laterally inward of the second charge-blocking material. Insulative charge-passage material is formed laterally inward of the storage material. Channel material is formed to extend elevationally along the insulative tiers and the wordline tiers laterally inward of the insulative charge-passage material. Structure embodiments are disclosed.

Abstract: A memory device includes a first layer, wherein the first layer includes a first memory array, a first row decoder circuit, and a first column sensing circuit. The memory device includes a second layer disposed with respect to the first layer in a vertical direction. The second layer includes a first peripheral circuit operatively coupled to the first memory array, the first row decoder circuit, and the first column sensing circuit. The memory device includes a plurality of interconnect structures extending along the vertical direction. At least a first one of the plurality of interconnect structures operatively couples the second layer to the first layer.

Abstract: A semiconductor memory device includes an electrode structure, a plurality of channel posts, and at least one gate separation layer. The electrode structure includes insulating interlayers and gate conductive layers which are alternately stacked. The channel posts are formed through the electrode structure. The gate separation layer is formed between the channel posts. The gate separation layer separates an uppermost gate conductive layer among the gate conductive layers. Each channel post among the channel posts adjacent to the gate separation layer has a gibbous moon shape in a planar view. The semiconductor memory device further includes a slit structure arranged at both sides of the gate separation layer. The slit structure is formed through the electrode structure. Each channel post among the channel posts adjacent to the slit structure has a gibbous moon shape in the planar view.

Abstract: A three-dimensional (3D) memory device includes a substrate, an alternating conductive/dielectric stack disposed on the substrate, an epitaxial layer disposed on the substrate, a blocking layer disposed on the epitaxial layer and surrounded by the alternating conductive/dielectric stack, a trapping layer disposed on and surrounded by the blocking layer, a tunneling layer disposed on and surrounded by the trapping layer, and a semiconductor layer disposed on and in contact with the epitaxial layer and partially disposed on and surrounded by the tunneling layer.

Abstract: A semiconductor device includes a substrate including a cell region and a peripheral region, a cell stacked structure stacked on the substrate in the cell region, a channel layer in one structure penetrating the cell stacked structure, a driving transistor formed in the peripheral region, and a plug structure coupled to the driving transistor and including a stacking structure of at least two contact plugs shorter than the channel layer, wherein each of the contact plugs is arranged at a same height as a part of the cell stacked structure.

Abstract: A field-effect transistor includes a gate structure comprising a structure in which a first insulating layer, a first gate electrode, and a second insulating layer are sequentially stacked on a first conductive layer, the gate structure surrounding a first hole through the first insulating layer and exposing a part of the first conductive layer; a second conductive layer on the second insulating layer and surrounding a second hole connected to the first hole and exposing a part of the first conductive layer; a first gate insulating layer covering an inner wall of the gate structure exposed by the first hole; a semiconductor layer covering a part of the first conductive layer exposed through the first hole and the second hole, the first gate insulating layer, and the second conductive layer; a second gate insulating layer covering the semiconductor layer; and a second gate electrode filling the first and second holes.

Abstract: A method of fabricating an electronic device including a semiconductor memory includes forming a first conductive structure extending in a first direction and having a closed-loop shape, forming a second conductive structure extending in a second direction and having a closed-loop shape, the second direction intersecting the first direction, forming a memory cell located at an intersection of the first conductive structure and the second conductive structure, forming first conductive patterns extending in the first direction by etching an end portion of the first conductive structure, forming second conductive patterns extending in the second direction by etching an end portion of the second conductive structure, forming a first protective layer on an etched surface of each of the first conductive patterns and the second conductive patterns, and forming a gap-fill layer on the first protective layer.

Abstract: Embodiments of bonded unified semiconductor chips and fabrication and operation methods thereof are disclosed. In an example, a method for forming a unified semiconductor chip is disclosed. A first semiconductor structure is formed. The first semiconductor structure includes one or more processors, an array of embedded DRAM cells, and a first bonding layer including a plurality of first bonding contacts. A second semiconductor structure is formed. The second semiconductor structure includes an array of NAND memory cells and a second bonding layer including a plurality of second bonding contacts. The first semiconductor structure and the second semiconductor structure are bonded in a face-to-face manner, such that the first bonding contacts are in contact with the second bonding contacts at a bonding interface.

Abstract: In some embodiments, a memory array comprising strings of memory cells comprise laterally-spaced memory blocks individually comprising a vertical stack comprising alternating insulative tiers and conductive tiers. Operative channel-material strings of memory cells extend through the insulative tiers and the conductive tiers. Insulative pillars are laterally-between and longitudinally-along immediately-laterally-adjacent of the memory blocks. The pillars comprise vertically-spaced and radially-projecting insulative rings in the conductive tiers as compared to the insulative tiers. Other embodiments, including methods, are disclosed.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes a memory stack including interleaved stack conductive layers and stack dielectric layers, a semiconductor layer, a plurality of channel structures each extending vertically through the memory stack into the semiconductor layer, and an insulating structure extending vertically through the memory stack and including a dielectric layer doped with at least one of hydrogen or an isotope of hydrogen.

Abstract: Some embodiments include an integrated assembly having a first structure containing semiconductor material, and having a second structure contacting the first structure. The first structure has a composition along an interface with the second structure. The composition includes additive to a concentration within a range of from about 1018 atoms/cm3 to about 1021 atoms/cm3. The additive includes one or more of carbon, oxygen, nitrogen and sulfur. Some embodiments include methods of forming integrated assemblies.

Abstract: A method of forming a microelectronic device comprises forming a stack structure comprising vertically alternating insulating structures and conductive structures arranged in tiers. Each of the tiers individually comprises one of the insulating structures and one of the conductive structures. A sacrificial material is formed over the stack structure and pillar structures are formed to extend vertically through the stack structure and the sacrificial material. The method comprises forming conductive plug structures within upper portions of the pillar structures, forming slots extending vertically through the stack structure and the sacrificial material, at least partially removing the sacrificial material to form openings horizontally interposed between the conductive plug structures, and forming a low-K dielectric material within the openings. Microelectronic devices, memory devices, and electronic systems are also described.

Abstract: A microelectronic device comprises a stack structure comprising a vertically alternating sequence of conductive structures and insulative structures arranged in tiers, the stack structure divided into block structures separated from one another by slot structures, a staircase structure within the stack structure having steps comprising horizontal edges of the tiers, conductive contact structures in contact with the steps of the staircase structure, support pillar structures extending through the stack structure, and additional slot structures extending partially through the stack structure within one of the block structures, one of the additional slot structures extending between horizontally neighboring support pillar structures and closer to one of the horizontally neighboring support pillar structures than to an additional one of the horizontally neighboring support pillar structures. Related microelectronic devices, memory devices, and electronic systems are also described.

Abstract: An electronic device is disclosed. The electronic device includes a conductor, and a conductive oxide material electrically connected to the conductor. The conductive oxide materials is substantially amorphous, and the conductive oxide material includes first and second oxide materials. In addition, the first oxide material is different from the second oxide material. The electronic device also includes a second material, electrically connected to the conductive oxide material.

Abstract: A semiconductor device includes a substrate. The semiconductor device includes a dielectric layer disposed over a portion of the substrate. The semiconductor device includes a diffusion blocking layer disposed over the dielectric layer. The diffusion blocking layer and the dielectric layer have different material compositions. The semiconductor device includes a ferroelectric layer disposed over the diffusion blocking layer.

Abstract: Embodiments of a three-dimensional (3D) memory device are provided. The 3D memory device includes a stack structure over a substrate. The stack structure includes a plurality of conductor layers insulated from one another by a gate-to-gate dielectric structure. The gate-to-gate dielectric structure includes a gate-to-gate dielectric layer between adjacent conductor layers along a vertical direction perpendicular to a top surface of the substrate. The 3D memory device also includes a channel structure extending in the stack structure. The channel structure includes a memory layer that protrudes towards the gate-to-gate dielectric layer.

Abstract: Embodiments of semiconductor devices and methods for forming the semiconductor devices are disclosed. In an example, a method for forming device openings includes forming a material layer over a first region and a second region of a substrate, the first region being adjacent to the second region, forming a mask layer over the material layer, the mask layer covering the first region and the second region, and forming a patterning layer over the mask layer. The patterning layer covers the first region and the second region and including openings corresponding to the first region. The plurality of openings includes a first opening adjacent to a boundary between the first region and the second region and a second opening further away from the boundary. Along a plane parallel to a top surface of the substrate, a size of the first opening is greater than a size of the second opening.

Abstract: Three-dimensional (3D) NAND memory devices and methods are provided. In one aspect, a fabrication method includes depositing a cover layer over a substrate, depositing a layer stack over the cover layer, performing a first epitaxial growth to deposit a first epitaxial layer on a side portion of a channel layer that extends through the layer stack, removing the cover layer to expose a portion of the substrate, performing a second epitaxial growth to deposit a second epitaxial layer on the portion of the substrate, and performing a third epitaxial growth to deposit a third epitaxial layer on the second epitaxial layer. The second and third epitaxial layers are configured to provide separate electrical current paths for an erase operation and a read operation.