A semiconductor memory device according to an embodiment includes: a stacked body alternately stacking first insulating layers and gate electrode layers in a first direction; first to third semiconductor layers in the stacked body extending in the first direction; first to third charge accumulation layers; and a second insulating layer in the stacked body extending in the first direction, the second insulating layer contacting the first semiconductor layer or the first charge accumulation layer in a plane perpendicular to the first direction. A first distance between two end surfaces of the gate electrode layer monotonically increases in the first direction in a first cross section parallel to the first direction. A second distance between two end surfaces of the gate electrode layer monotonically increases in the first direction, decreases, and then monotonically increases in a second cross section parallel to the first direction different from the first cross section.

A device area and a marking area neighboring the device area over a dielectric stack are determined. The dielectric stack includes insulating material layers and sacrificial material layers arranged alternatingly over a substrate. The device area and the marking area are patterned using a same etching process to form a marking pattern having a central marking structure in a marking area and a staircase pattern in the device area. The marking pattern and the staircase pattern have a same thickness equal to a thickness of at least one insulating material layer and one sacrificial material layer, and the central marking structure divides the marking area into a first marking sub-area farther from the device area and a second marking sub-area closer to the device area. A first pattern density of the first marking sub-area is greater than or equal to a second pattern density of the second marking sub-area. A photoresist layer is formed to cover the staircase pattern and expose the marking pattern, and the photoresist layer is trimmed to expose a portion of the dielectric stack along a horizontal direction. An etching process is performed to maintain the marking pattern and remove the exposed portion of the dielectric stack and form a staircase.

A semiconductor structure includes a semiconductor substrate, at least one raised dummy feature, at least one memory cell, and at least one word line. The raised dummy feature is present on the semiconductor substrate and defines a cell region on the semiconductor substrate. The memory cell is present on the cell region. The word line is present adjacent to the memory cell.

A semiconductor memory device comprises: a plurality of first conductive layers arranged separated from each other in a first direction; a plurality of second conductive layers arranged, electrically insulated from the plurality of first conductive layers, at a different position in a second direction intersecting the first direction with respect to the first conductive layers; a plurality of memory structures; and a source structure. Respective one ends of the plurality of memory structures and one end of the source structure are electrically connected. The respective other ends of the plurality of memory structures are respectively electrically connected to different first wirings of a plurality of first wirings formed in the same layer in the first direction. The other end of the source structure is electrically connected to a second wiring formed in a different layer from the plurality of first wirings in the first direction.

A semiconductor memory device comprises: a plurality of first conductive layers arranged separated from each other in a first direction; a plurality of second conductive layers arranged, electrically insulated from the plurality of first conductive layers, at a different position in a second direction intersecting the first direction with respect to the first conductive layers; a plurality of memory structures; and a source structure. Respective one ends of the plurality of memory structures and one end of the source structure are electrically connected. The respective other ends of the plurality of memory structures are respectively electrically connected to different first wirings of a plurality of first wirings formed in the same layer in the first direction. The other end of the source structure is electrically connected to a second wiring formed in a different layer from the plurality of first wirings in the first direction.

Disclosed is a method of manufacturing a semiconductor device, including: forming a slacked structure including first material layers and second material layers alternately stacked on each other; forming a pillar passing through the stacked structure, the pillar including a protruding portion protruding above an uppermost surface of the stacked structure; forming a conductive layer surrounding the protruding portion of the pillar; and forming a conductive pattern in contact with the protruding portion of the pillar by oxidizing a surface of the conductive layer.

A semiconductor memory device includes a substrate with a cell array region and a connection region, an electrode structure including electrodes stacked on the substrate and having a staircase structure on the connection region, a vertical channel structure on the cell array region to penetrate the electrode structure and electrically connected to the substrate, a dummy structure on the connection region to penetrate the staircase structure, and a first sidewall oxide pattern interposed between the substrate and the dummy structure. The dummy structure includes an upper portion that is on the substrate, a middle portion that is in contact with the first sidewall oxide pattern, and a lower portion that is below the middle portion. With increasing vertical distance from the upper portion, a diameter of the middle portion decreases until it reaches its smallest value and then increases.

A vertical memory device includes a substrate including a cell region and a peripheral circuit region, gate electrodes sequentially stacked on the cell region of the substrate in a vertical direction substantially perpendicular to an upper surface of the substrate, a channel on the cell region and extending through the gate electrodes in the vertical direction, a first lower contact plug on the peripheral circuit region and extending in the vertical direction, a second lower contact plug on the peripheral circuit region adjacent to the first lower contact plug and extending in the vertical direction, and a first upper wiring electrically connected to the first lower contact plug. The first upper wiring is configured to and apply an electrical signal to the first lower contact plug. The second lower contact plug is not electrically connected to an upper wiring configured to apply an electrical signal.

A semiconductor memory device with a three-dimensional (3D) structure may include: a cell region arranged over a substrate, including a cell structure; a peripheral circuit region arranged between the substrate and the cell region; an upper wiring structure arranged over the cell region; main channel films and dummy channel films formed through the cell structure. The dummy channel films are suitable for electrically coupling the upper wiring structure.

A semiconductor memory device with a three-dimensional (3D) structure may include: a cell region arranged over a substrate, including a cell structure; a peripheral circuit region arranged between the substrate and the cell region; an upper wiring structure arranged over the cell region; main channel films and dummy channel films formed through the cell structure. The dummy channel films are suitable for electrically coupling the upper wiring structure.