Merging schemes in semiconductive devices
The present disclosure relates methods, devices, systems, and techniques for merging schemes in semiconductor devices such as three-dimensional (3D) semiconductor devices. In one aspect, a semiconductor device includes a semiconductor structure that includes a stack of conductive layers and insulating layers alternating with each other along a first direction. The semiconductor structure includes an array region and a connection region adjacent to the array region in a second direction perpendicular to the first direction. The semiconductor device further includes multiple contact structures extending through the connection region along the first direction. Each conductive layer in the stack of conductive layers and insulating layers is coupled to a corresponding contact structure of the multiple contact structures and isolated from one or more other contact structures of the multiple contact structures. Each contact structure of the multiple contact structures includes a body and a head extending beyond the body.
1 . A semiconductor device, comprising:
a semiconductor structure comprising a stack of conductive layers and insulating layers alternating with each other along a first direction, wherein the semiconductor structure comprises an array region and a connection region adjacent to the array region in a second direction perpendicular to the first direction; and
multiple contact structures extending through the connection region along the first direction,
wherein each conductive layer in the stack of conductive layers and insulating layers is coupled to a corresponding contact structure of the multiple contact structures and isolated from one or more other contact structures of the multiple contact structures, and
wherein each contact structure of the multiple contact structures comprises a body and a head extending beyond the body, an end of the head is in contact with an end of the body, and the end of the body is wider than the end of the head.
2 . The semiconductor device of claim 1 , wherein the body comprises an outer layer, an inner layer, and an intermediate layer between the outer layer and the inner layer, the head comprises an outer layer, an inner layer, and an intermediate layer between the outer layer and the inner layer, and the outer layer of the body, the intermediate layer of the body, and the inner layer of the body are continuously connected with the outer layer of the head, the intermediate layer of the head, and the inner layer of the head, respectively.
3 . The semiconductor device of claim 2 , wherein the outer layer of the body comprises a high-k dielectric material, the intermediate layer of the body comprises a titanium nitride material, the inner layer of the body comprises a conductive material, the outer layer of the head comprises a high-k dielectric material, the intermediate layer of the head comprises a titanium nitride material, and the inner layer of the head comprises a conductive material.
4 . The semiconductor device of claim 1 , wherein the contact structure extends through a set of conductive layers of the stack of conductive layers and insulating layers, wherein the contact structure is in contact with one conductive layer of the set of conductive layers that is closest to the head of the contact structure among the set of conductive layers, and wherein a contact spacer comprising a dielectric material is located between the contact structure and one or more other conductive layers of the set of conductive layers that are isolated from the contact structure.
5 . The semiconductor device of claim 4 , further comprising gate line slits and channel structures both extending through the semiconductor structure along the first direction.
6 . The semiconductor device of claim 1 , wherein the semiconductor structure comprises one or more decks that are sequentially stacked together along the first direction, and
wherein the body of the contact structure comprises one or more segments that are sequentially connected together along the first direction, and each of the one or more segments is shaped like a truncated cone and corresponds to a respective deck of the one or more decks of the semiconductor structure.