There is formed, on a stack formed by alternately stacking an oxide film and a nitride film or an oxide film and a polysilicon film on a substrate, a hard mask in which two or more kinds of lines made of mutually different materials are arranged in order. Then, a photoresist is applied onto the hard mask. Furthermore, the photoresist is trimmed until one line is exposed from the end of the hard mask. Moreover, one line of the hard mask exposed beneath the photoresist is etched. Furthermore, a part of the stack exposed beneath the hard mask is etched. The etching of the photoresist, the hard mask, and the stack is repeated while changing etching conditions.

Embodiments of structures and methods for forming three-dimensional (3D) memory devices are provided. In an example, a 3D memory device includes a core region and a staircase region. The staircase region includes a plurality of stairs each has at least a conductor/dielectric pair extending in a lateral direction. The staircase region includes a drain-select-gate (DSG) cut structure extending along the lateral direction and a vertical direction, and a plurality of support structures extending in the DSG structure along the vertical direction. Of at least one of the support structures, a dimension along the lateral direction is greater than a dimension along a second lateral direction perpendicular to the lateral direction.

In a method of manufacturing a semiconductor device, a memory cell structure covered by a protective layer is formed in a memory cell area of a substrate. A mask pattern is formed. The mask pattern has an opening over a first circuit area, while the memory cell area and a second circuit area are covered by the mask pattern. The substrate in the first circuit area is recessed, while the memory cell area and the second circuit area are protected. A first field effect transistor (FET) having a first gate dielectric layer is formed in the first circuit area over the recessed substrate and a second FET having a second gate dielectric layer is formed in the second circuit area over the substrate as viewed in cross section.

Methods, systems and apparatus for memory devices with multiple string select line (SSL) cuts are provided. In one aspect, a semiconductor device includes: a three-dimensional (3D) array of memory cells and a plurality of common source lines (CSLs) configured to separate the 3D array of memory cells into a plurality of portions. Each portion of the plurality of portions is between two adjacent CSLs and includes a plurality of conductive layers separated from each other by insulating layers and a plurality of vertical channels arranged orthogonally through the plurality of conductive layers and the insulating layers, each of the plurality of vertical channels including a string of memory cells. A top part of each portion of one or more portions includes at least two SSL cuts configured to separate the portion into multiple independent units, and each of the independent units is selectable by a corresponding SSL of multiple SSLs.

Semiconductor devices may include a gate stack including electrode layers stacked alternately with insulating layers and channel structures in the electrode layers and the insulating layers; a cell region insulating layer and an upper support layer on the gate stack; and a separation region in the gate stack and the cell region insulating layer. The separation regions may include a first separation region in the upper support layer and a second separation region below the upper support layer. The first separation region may include a first region in the upper support layer, a second region in the cell region insulating layer, and a third region in the gate electrode layers. The first separation region may further include has a first bend portion in the second region and a second bend portion that may be higher than the first bend portion and uppermost surfaces of the channel structures.

A semiconductor device includes a first substrate structure including a substrate, circuit elements, and first bonding metal layers, and a second substrate structure connected to the first substrate structure. The second substrate structure includes a plate layer, gate electrodes stacked in a first direction below the plate layer, separation regions penetrating through the gate electrodes and extending in a second direction and spaced apart from each other in the second direction, an insulating region extending from an upper surface of the plate layer and penetrating through the plate layer and at least one of the gate electrodes between the separation regions, and second bonding metal layers connected to the first bonding metal layers. The insulating region has inclined side surfaces such that a width of the insulating region decreases in a direction toward the first substrate structure.

Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatus includes a first conductive contact; a second conductive contact; levels of conductive materials stacked over one another and located over the first and second conductive contacts; levels of dielectric materials interleaved with the levels of the conductive materials, the levels of conductive materials and the levels of dielectric materials formed a stack of materials; a first conductive structure located on a first side of the stack of materials and contacting the first conductive contact and a first level of conductive material of the levels of conductive materials; and a second conductive structure located on a second side of the stack of materials and contacting the second conductive contact and a second level of conductive material of the levels of conductive materials.

A semiconductor device includes a first substrate, circuit devices disposed on the first substrate, a first interconnection structure electrically connected to the circuit devices, a second substrate disposed on an upper portion of the first interconnection structure, gate electrodes spaced apart from each other and stacked on the second substrate in a direction perpendicular to an upper surface of the second substrate, and channel structures penetrating the gate electrodes, extending perpendicularly to the second substrate, and including a channel layer. The semiconductor device also includes a ground interconnection structure connecting the first substrate and the second substrate, and including an upper via integrated with the second substrate and extending from a lower surface of the second substrate towards the first substrate.

A method for forming a staircase structure of 3D memory, including: forming an alternating layer stack comprising a plurality of dielectric layer pairs disposed over a substrate; forming a first mask stack over the alternating layer stack; patterning the first mask stack to define a staircase region comprising a number of N sub-staircase regions over the alternating layer stack using a lithography process and N is greater than 1; forming a first staircase structure over the staircase region, the first staircase structure has a number of M steps at each of the staircase regions and M is greater than 1; and forming a second staircase structure on the first staircase structure, the second staircase structure has a number of 2*N*M steps at the staircase region.

Embodiments of a three-dimensional (3D) memory device and fabrication methods thereof are disclosed. In an example, a 3D memory device includes a memory stack having a plurality of stairs. Each stair may include interleaved one or more conductor layers and one or more dielectric layers. Each of the stairs includes one of the conductor layers on a top surface of the stair, the one of the conductor layers having (i) a bottom portion in contact with one of the dielectric layers, and (ii) a top portion exposed by the memory stack and in contact with the bottom portion. A lateral dimension of the top portion may be less than a lateral dimension of the bottom portion. An end of the top portion that may be facing away from the memory stack laterally exceeds the bottom portion by a distance.