A memory device includes a substrate, a first dielectric structure, a second dielectric structure, a channel structure, a source structure, and a drain structure. The first dielectric structure and the second dielectric structure are disposed on the substrate, and are spaced apart from each other in a first direction. The channel structure interconnects the first dielectric structure and the second dielectric structure. The source structure and the drain structure are on opposite ends of the channel structure, and are respectively embedded in the first dielectric structure and the second dielectric structure, wherein a ratio in length along the first direction of the source structure to the first dielectric structure is between 0.3 and 0.4.

A semiconductor memory device includes multiple first electrode layers stacked in a first direction, multiple second electrode layers stacked in the first direction, a first columnar body extending through the multiple first electrode layers in the first direction, a second columnar body extending through the multiple second electrode layers in the first direction, a connection part connecting the first columnar body and the second columnar body, and a spacer film having an island configuration surrounding the connection part. The multiple first electrode layers and the multiple second electrode layers are arranged in the first direction, and the connection part and the spacer film are provided between the multiple first electrode layers and the multiple second electrode layers.

A non-volatile memory device includes a substrate having a cell array region and an extension region. A mold structure includes a plurality of gate electrodes and a plurality of mold insulating layers alternately stacked on the substrate such that the mold structure has a step shape that steps downwardly in the extension region in a direction away from the cell array region. A channel structure penetrates through the mold structure in the cell array region, and a cell contact structure penetrates through the mold structure in the extension region. A portion of the cell contact structure is in contact with a portion of an uppermost one of the gate electrodes. The cell contact structure includes a first portion in contact with a side surface of the uppermost one of the gate electrodes and a second portion in contact with a top surface of the uppermost one of the gate electrodes. A width of the first portion is smaller than a width of the second portion.

A non-volatile memory device includes a substrate having a cell array region and an extension region. A mold structure includes a plurality of gate electrodes and a plurality of mold insulating layers alternately stacked on the substrate such that the mold structure has a step shape that steps downwardly in the extension region in a direction away from the cell array region. A channel structure penetrates through the mold structure in the cell array region, and a cell contact structure penetrates through the mold structure in the extension region. A portion of the cell contact structure is in contact with a portion of an uppermost one of the gate electrodes. The cell contact structure includes a first portion in contact with a side surface of the uppermost one of the gate electrodes and a second portion in contact with a top surface of the uppermost one of the gate electrodes. A width of the first portion is smaller than a width of the second portion.

A three-dimensional semiconductor memory device is provided. The device may include a first stack structure on a substrate including a cell array region and a connection region, a second stack structure on the first stack structure, a first vertical channel hole penetrating the first stack structure and partially exposing the substrate and a bottom surface of the second stack structure, on the cell array region, a second vertical channel hole penetrating the second stack structure and exposing the first vertical channel hole, on the cell array region, a bottom diameter of the second vertical channel hole being smaller than an top diameter of the first vertical channel hole, and a buffer pattern placed in the first vertical channel hole and adjacent to the bottom surface of the second stack structure.

A method of forming a microelectronic device includes forming a microelectronic device structure. The microelectronic device structure includes a stack structure comprising insulative structures and electrically conductive structures vertically alternating with the insulative structures, pillar structures extending vertically through the stack structure, an etch stop material vertically overlaying the stack structure, and a first dielectric material vertically overlying the etch stop material. The method further includes removing portions of the first dielectric material, the etch stop material, and an upper region of the stack structure to form a trench interposed between horizontally neighboring groups of the pillar structures, forming a liner material within the trench, and substantially filling a remaining portion of the trench with a second dielectric material to form a dielectric barrier structure.

A method of forming a microelectronic device includes forming a microelectronic device structure. The microelectronic device structure includes a stack structure comprising insulative structures and electrically conductive structures vertically alternating with the insulative structures, pillar structures extending vertically through the stack structure, an etch stop material vertically overlaying the stack structure, and a first dielectric material vertically overlying the etch stop material. The method further includes removing portions of the first dielectric material, the etch stop material, and an upper region of the stack structure to form a trench interposed between horizontally neighboring groups of the pillar structures, forming a liner material within the trench, and substantially filling a remaining portion of the trench with a second dielectric material to form a dielectric barrier structure.

A nonvolatile memory device includes a substrate including a cell array region, a first gate electrode including an opening on the cell array region of the substrate, a plurality of second gate electrodes stacked above the first gate electrode and including convex portions having an outward curve extending toward the substrate, and a word line cutting region cutting the opening and the convex portions.

A nonvolatile memory device includes a substrate including a cell array region, a first gate electrode including an opening on the cell array region of the substrate, a plurality of second gate electrodes stacked above the first gate electrode and including convex portions having an outward curve extending toward the substrate, and a word line cutting region cutting the opening and the convex portions.

A device includes a stack above a substrate in a first direction perpendicular to a surface of the substrate, the stack including conductive layers; a semiconductor layer neighboring the stack in a second direction parallel to the surface of the substrate; a memory layer between the first stack and the semiconductor layer; memory cells between the conductive layers and the semiconductor layer; a first transistor connected between one end of the semiconductor layer in a third direction parallel to the surface of the substrate and crossing the second direction and a first interconnect in the first direction; and a second transistor connected between the other end of the semiconductor layer and a second interconnect in the first direction.