A ferroelectric memory device includes a multi-layer stack, a ferroelectric layer, and channel layers. The multi-layer stack is disposed on a substrate and includes conductive layers and dielectric layers stacked alternately. The ferroelectric layer has a curvy profile and is disposed along sidewalls of the conducive layers and sidewalls of the dielectric layers. The channel layers are separated from each other and disposed on the ferroelectric layer, and correspond to the conductive layers respectively.

A ferroelectric memory device includes a multi-layer stack, a ferroelectric layer, and channel layers. The multi-layer stack is disposed on a substrate and includes conductive layers and dielectric layers stacked alternately. The ferroelectric layer has a curvy profile and is disposed along sidewalls of the conducive layers and sidewalls of the dielectric layers. The channel layers are separated from each other and disposed on the ferroelectric layer, and correspond to the conductive layers respectively.

A memory device includes a first etch stop layer, an etch stop pattern, a second etch stop layer, a plurality of stacks and a first conductive pillar. The etch stop pattern is disposed in the first etch stop layer. The second etch stop layer is disposed on the first etch stop layer and the etch stop pattern, wherein a material of the etch stop pattern is different from a material of the first etch stop layer and a material of the second etch stop layer. The stacks are disposed on the second etch stop layer. The first conductive pillar is disposed between the stacks, wherein the first conductive pillar extends along the stacks and the second etch stop layer to be in physical contact with the etch stop pattern.

A memory device includes a first etch stop layer, an etch stop pattern, a second etch stop layer, a plurality of stacks and a first conductive pillar. The etch stop pattern is disposed in the first etch stop layer. The second etch stop layer is disposed on the first etch stop layer and the etch stop pattern, wherein a material of the etch stop pattern is different from a material of the first etch stop layer and a material of the second etch stop layer. The stacks are disposed on the second etch stop layer. The first conductive pillar is disposed between the stacks, wherein the first conductive pillar extends along the stacks and the second etch stop layer to be in physical contact with the etch stop pattern.

A memory device includes a first conductive via, a first conductive line, an etch stop layer, a plurality of stacks and a first conductive pillar. The first conductive line is disposed on and in physical contact with the first conductive via. The etch stop layer is disposed on and in physical contact with the first conductive line. The stacks are disposed on the etch stop layer. The first conductive pillar is disposed between the stacks. The first conductive pillar extends between opposite surfaces of the stacks to be in physical contact with the first conductive line.

A memory device includes a first conductive via, a first conductive line, an etch stop layer, a plurality of stacks and a first conductive pillar. The first conductive line is disposed on and in physical contact with the first conductive via. The etch stop layer is disposed on and in physical contact with the first conductive line. The stacks are disposed on the etch stop layer. The first conductive pillar is disposed between the stacks. The first conductive pillar extends between opposite surfaces of the stacks to be in physical contact with the first conductive line.

A transistor includes a gate, a channel layer, a gate insulation layer, a passivation layer, a liner, a first signal line, and a second signal line. The first signal line is embedded in the passivation layer to form a first via in the passivation layer and overlapping the channel layer. The second signal line is embedded in the passivation layer to form a second via in the passivation layer overlapping the channel layer. The second signal line is in contact with the channel layer. The liner includes an insulation region and a conductive region connected with the insulation region. The insulation region is disposed over the passivation layer and on sidewalls of the first via. The conductive region is disposed under a bottom of the first via and connected with the channel layer. The first signal line is electrically connected with the channel layer through the conductive region.

A transistor includes a gate, a channel layer, a gate insulation layer, a passivation layer, a liner, a first signal line, and a second signal line. The first signal line is embedded in the passivation layer to form a first via in the passivation layer and overlapping the channel layer. The second signal line is embedded in the passivation layer to form a second via in the passivation layer overlapping the channel layer. The second signal line is in contact with the channel layer. The liner includes an insulation region and a conductive region connected with the insulation region. The insulation region is disposed over the passivation layer and on sidewalls of the first via. The conductive region is disposed under a bottom of the first via and connected with the channel layer. The first signal line is electrically connected with the channel layer through the conductive region.

In an embodiment, a device includes: a first word line over a substrate, the first word line including a first conductive material; a first bit line intersecting the first word line; a first memory film between the first bit line and the first word line; and a first conductive spacer between the first memory film and the first word line, the first conductive spacer including a second conductive material, the second conductive material having a different work function than the first conductive material, the first conductive material having a lower resistivity than the second conductive material.

A semiconductor device includes a first memory cell that includes: a first conductor structure extending along a first lateral direction; a first portion of a first memory film wrapping around a first portion of the first conductor structure; a first semiconductor film wrapping around the first portion of the first memory film; a second conductor structure extending along a vertical direction and coupled to a first sidewall of the first semiconductor film, wherein the first sidewall faces toward or away from a second lateral direction perpendicular to the first lateral direction; and a third conductor structure extending along the vertical direction and coupled to a second sidewall of the first semiconductor film, wherein the second sidewall faces toward or away from the second lateral direction.