Abstract: In a method for fabricating a semiconductor device, an initial stack of sacrificial word line layers and insulating layers is formed over a substrate of the semiconductor device. The sacrificial word line layers and the insulating layers are disposed over the substrate alternately. A first staircase is formed in a first staircase region of a connection region of the initial stack. A second staircase is formed in a second staircase region of the connection region of the initial stack. The connection region of the initial stack includes a separation region between the first and second staircases, and the connection region is positioned between array regions of the initial stack at opposing sides of the initial stack.

Abstract: Staircase structures for a three-dimensional (3D) memory device are disclosed. In some embodiments, the method includes disposing an alternating dielectric stack on a substrate with first and second dielectric layers alternatingly stacked on top of each other. Next, multiple division blocks can be formed in a staircase region. Each division block includes a first plurality of staircase steps in the first direction. Each staircase step in the first direction has two or more dielectric layer pairs. Then, a second plurality of staircase steps along a second direction, perpendicular to the first direction, can be formed. Each staircase step in the second direction includes the first plurality of staircase steps along the first direction. The method further includes forming an offset number of dielectric layer pairs between the multiple division blocks such that each dielectric layer pair is accessible from a top surface of a staircase step.

Abstract: Three-dimensional (3D) NAND memory devices and methods are provided. In one aspect, a 3D NAND memory device includes a substrate, a layer stack, memory cells, a semiconductor layer, a contact structure, and gate line slit structures. The substrate includes a doped region. The layer stack is formed over the substrate. The memory cells are formed through the layer stack over the substrate. The semiconductor layer is formed on the doped region and a side portion of a channel layer that extends through the layer stack. The contact structure electrically contacts the doped region. A dielectric material is filled in the gate line slit structures. Air gaps are formed in the gate line slit structures by the dielectric material.

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 and a plurality of memory strings. The memory stack includes interleaved conductive layers and dielectric layers. Each memory string extends vertically through the memory stack. The plurality of memory strings are divided into a plurality of regions of the memory stack in a plan view. The conductive layers include one or more drain select gate (DSG) lines configured to control drains of the plurality of memory strings. The numbers of the DSG lines are different among the plurality of regions. Each of the plurality of memory strings has a nominally same height.

Abstract: Embodiments of 3D memory devices having staircase structures and methods for forming the same are disclosed. In an example, a 3D memory device includes a memory array structure and a staircase structure in an intermediate of the memory array structure. The staircase structure includes a plurality of stairs extending along the lateral direction, and a bridge structure in contact with the first memory array structure and the second memory array structure. The plurality of stairs includes a stair above one or more dielectric pairs The stair includes a conductor portion on a top surface of the stair and in contact with and electrically connected to the bridge structure, and is electrically connected to at least one of a first memory array structure and a second memory array structure of the memory array structure through the bridge structure. Along a second lateral direction, a width of the conductor portion is unchanged.

Abstract: Embodiments of 3D memory devices having staircase structures and methods for forming the same are disclosed. In an example, the 3D memory device includes a memory array structure and a staircase structure. The staircase structure is located in an intermediate of the memory array structure and divides the memory array structure into a first memory array structure and a second memory array structure along a lateral direction. The staircase structure includes a plurality of stairs extending along the lateral direction, and a bridge structure in contact with the memory array structure. The stairs include a stair above one or more dielectric pairs. The stair includes a conductor portion electrically connected to the bridge structure and is electrically connected to the memory array structure through the bridge structure. Along a second lateral direction perpendicular to the lateral direction and away from the bridge structure, a width of the conductor portion decreases.

Abstract: Memory device includes a bottom-select-gate (BSG) structure formed on a substrate. Cut slits are formed vertically through the BSG structure. 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: Aspects of the disclosure provide a semiconductor device and a method for fabricating the same. The method for fabricating the semiconductor device can include forming a stack of alternating first insulating layers and first sacrificial layers over a semiconductor substrate, and forming a staircase in the stack having a plurality of steps, with at least a first step of the staircase including a first sacrificial layer of the first sacrificial layers over a first insulating layer of the first insulating layers. Further, the method can include forming a recess in the first sacrificial layer, forming a second sacrificial layer in the recess, and replacing a portion of the first sacrificial layer and the second sacrificial layer with a conductive material that forms a contact pad.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a method for forming a 3D memory device is disclosed. A sacrificial layer on a substrate, a first stop layer on the sacrificial layer, an N-type doped semiconductor layer on the first stop layer, and a dielectric stack on the N-type doped semiconductor layer are sequentially formed. A plurality of channel structures each extending vertically through the dielectric stack and the N-type doped semiconductor layer are formed, stopping at the first stop layer. The dielectric stack is replaced with a memory stack, such that each of the plurality of channel structures extends vertically through the memory stack and the N-type doped semiconductor layer. The substrate, the sacrificial layer, and the first stop layer are sequentially removed to expose an end of each of the plurality of channel structures. A conductive layer is formed in contact with the ends of the plurality of channel structures.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a method for forming a 3D memory device is disclosed. A sacrificial layer on a substrate, an N-type doped semiconductor layer on the sacrificial layer, and a dielectric stack on the N-type doped semiconductor layer are subsequently formed. A channel structure extending vertically through the dielectric stack and the N-type doped semiconductor layer is formed. The dielectric stack is replaced with a memory stack, such that the channel structure extends vertically through the memory stack and the N-type doped semiconductor layer. The substrate and the sacrificial layer are removed to expose an end of the channel structure. Part of the channel structure abutting the N-type doped semiconductor layer is replaced with a semiconductor plug.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes a substrate, a peripheral circuit on the substrate, a memory stack including interleaved conductive layers and dielectric layers above the peripheral circuit, an N-type doped semiconductor layer above the memory stack, a plurality of channel structures each extending vertically through the memory stack into the N-type doped semiconductor layer, a conductive layer in contact with upper ends of the plurality of channel structures, at least part of which is on the N-type doped semiconductor layer, and a source contact above the memory stack and in contact with the N-type doped semiconductor layer.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes a substrate, a peripheral circuit on the substrate, a memory stack including interleaved conductive layers and dielectric layers above the peripheral circuit, an N-type doped semiconductor layer above the memory stack, a plurality of channel structures each extending vertically through the memory stack into the N-type doped semiconductor layer, and a source contact above the memory stack and in contact with the N-type doped semiconductor layer. An upper end of each of the plurality of channel structures is flush with or below a top surface of the N-type doped semiconductor layer.

Abstract: Aspects of the disclosure provide a method for data erase in a memory device. The method includes providing first erase carriers from a body portion for the memory cell string, during an erase operation in a memory cell string. The first erase carriers flow in a first direction from a source side of the memory cell string to a drain side of the memory cell string. Further, the method includes providing second erase carriers from a junction at the drain side of the memory cell string. The second erase carriers flow in a second direction from the drain side of the memory cell string to the source side of the memory cell string. Then, the method includes injecting the first erase carriers and the second erase carriers to charge storage portions of the memory cells in the memory cell string.

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: Memory device includes a bottom-select-gate (BSG) structure including cut slits 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. A first gate-line slit is between first and second finger regions and includes gate-line sub-slits. The first finger region is divided into a first string region and a second string region by a first cut-slit, formed in the first finger region along a second lateral direction and further extended into at least the second finger region along the first lateral direction. At least one BSG defined by the first cut-slit is located in at least the second finger region to connect to cell strings in the first string region through an inter-portion between adjacent gate-line sub-slits.

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: In a method for fabricating a semiconductor device, an initial stack is formed. The initial stack is formed of sacrificial layers and insulating layers that are alternatingly disposed over a substrate, and includes a first connection region, a first array region, and a second connection region that are disposed sequentially. A first initial staircase is formed in the first connection region and formed in a first group of sacrificial layers and insulating layers. A first top select gate staircase is formed in the second connection region, and formed in a second group of sacrificial layers and insulating layers. An etching process is subsequently performed in the first connection region to shift the first initial staircase toward the substrate along a vertical direction perpendicular to the substrate so as to form a first bottom select gate staircase.

Abstract: Aspects of the disclosure provide a semiconductor device. The semiconductor device includes gate layers and insulating layers that are stacked alternatingly along a direction perpendicular to a substrate of the semiconductor device and form a stack upon the substrate. The semiconductor device includes an array of channel structures that are formed in an array region of the stack. Further, the semiconductor device includes a first staircase formed of a first section of the stack in a connection region upon the substrate, and a second staircase formed of a second section of the stack in the connection region upon the substrate. In addition, the semiconductor device includes a dummy staircase formed of the first section of the stack and disposed between the first staircase and the second staircase in the connection region.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes a P-type doped region of a substrate, an N-type doped semiconductor layer on the P-type doped region, a memory stack including interleaved conductive layers and dielectric layers on the N-type doped semiconductor layer, a channel structure extending vertically through the memory stack and the N-type doped semiconductor layer into the P-type doped region, an N-type doped semiconductor plug extending vertically into the P-type doped region, and a source contact structure extending vertically through the memory stack to be in contact with the N-type doped semiconductor plug.

Abstract: Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes an N-type doped region of a substrate, an N-type doped semiconductor layer on the N-type doped region, a memory stack including interleaved conductive layers and dielectric layers on the N-type doped semiconductor layer, a channel structure extending vertically through the memory stack and the N-type doped semiconductor layer into the N-type doped region, and a source contact structure extending vertically through the memory stack and the N-type doped semiconductor layer into the N-type doped region. A first lateral dimension of a first portion of the source contact structure surrounded by the N-type doped region is greater than a second lateral dimension of a second portion of the source contact structure surrounded by the memory stack.