In an embodiment, a device includes: a pair of dielectric layers; a word line between the dielectric layers, sidewalls of the dielectric layers being recessed from a sidewall of the word line; a tunneling strip on a top surface of the word line, the sidewall of the word line, a bottom surface of the word line, and the sidewalls of the dielectric layers; a semiconductor strip on the tunneling strip; a bit line contacting a sidewall of the semiconductor strip; and a source line contacting the sidewall of the semiconductor strip.

In an embodiment, a device includes: a pair of dielectric layers; a word line between the dielectric layers, sidewalls of the dielectric layers being recessed from a sidewall of the word line; a tunneling strip on a top surface of the word line, the sidewall of the word line, a bottom surface of the word line, and the sidewalls of the dielectric layers; a semiconductor strip on the tunneling strip; a bit line contacting a sidewall of the semiconductor strip; and a source line contacting the sidewall of the semiconductor strip.

A memory cell includes patterning a first trench extending through a first conductive line, depositing a memory film along sidewalls and a bottom surface of the first trench, depositing a channel layer over the memory film, the channel layer extending along the sidewalls and the bottom surface of the first trench, depositing a first dielectric layer over and contacting the channel layer to fill the first trench, patterning a first opening, wherein patterning the first opening comprises etching the first dielectric layer, depositing a gate dielectric layer in the first opening, and depositing a gate electrode over the gate dielectric layer and in the first opening, the gate electrode being surrounded by the gate dielectric layer.

A memory cell includes patterning a first trench extending through a first conductive line, depositing a memory film along sidewalls and a bottom surface of the first trench, depositing a channel layer over the memory film, the channel layer extending along the sidewalls and the bottom surface of the first trench, depositing a first dielectric layer over and contacting the channel layer to fill the first trench, patterning a first opening, wherein patterning the first opening comprises etching the first dielectric layer, depositing a gate dielectric layer in the first opening, and depositing a gate electrode over the gate dielectric layer and in the first opening, the gate electrode being surrounded by the gate dielectric layer.

A semiconductor memory device includes a stack of alternating insulating layers and first conductive layers disposed over a substrate; a plurality of memory cell strings penetrating the stack over the substrate, each memory cell string comprising a central portion extending through the stack, a semiconductor layer surrounding the central portion, and a ferroelectric layer surrounding the semiconductor layer, and the central portion comprising a channel isolation structure and a second conductive layer and a third conductive layer at two sides of the channel isolation structure; and a plurality of cell isolation structures penetrating the conductive layers and the insulating layers over the substrate and disposed between two memory cell strings, each cell isolation structure comprising a top portion and a bottom portion adjoined to the top portion and different from the top portion.

A semiconductor memory device includes a stack of alternating insulating layers and first conductive layers disposed over a substrate; a plurality of memory cell strings penetrating the stack over the substrate, each memory cell string comprising a central portion extending through the stack, a semiconductor layer surrounding the central portion, and a ferroelectric layer surrounding the semiconductor layer, and the central portion comprising a channel isolation structure and a second conductive layer and a third conductive layer at two sides of the channel isolation structure; and a plurality of cell isolation structures penetrating the conductive layers and the insulating layers over the substrate and disposed between two memory cell strings, each cell isolation structure comprising a top portion and a bottom portion adjoined to the top portion and different from the top portion.

An illustrative device disclosed herein includes at least one layer of insulating material, a conductive contact structure having a conductive line portion and a conductive via portion and a memory cell positioned in a first opening in the at least one layer of insulating material. In this illustrative example, the memory cell includes a bottom electrode, a memory state material positioned above the bottom electrode and an internal sidewall spacer positioned within the first opening and above at least a portion of the memory state material, wherein the internal sidewall spacer defines a spacer opening and wherein the conductive via portion is positioned within the spacer opening and above a portion of the memory state material.

An illustrative device disclosed herein includes at least one layer of insulating material, a conductive contact structure having a conductive line portion and a conductive via portion and a memory cell positioned in a first opening in the at least one layer of insulating material. In this illustrative example, the memory cell includes a bottom electrode, a memory state material positioned above the bottom electrode and an internal sidewall spacer positioned within the first opening and above at least a portion of the memory state material, wherein the internal sidewall spacer defines a spacer opening and wherein the conductive via portion is positioned within the spacer opening and above a portion of the memory state material.

A memory cell includes a write bit line, a write transistor and a read transistor. The write transistor is coupled between the write bit line and a first node. The read transistor is coupled to the write transistor by the first node. The read transistor includes a ferroelectric layer. The write transistor is configured to set a stored data value of the memory cell by a write bit line signal that adjusts a polarization state of the read transistor. The polarization state corresponds to the stored data value.

In an embodiment, a device includes: a pair of dielectric layers; a word line between the dielectric layers, sidewalls of the dielectric layers being recessed from a sidewall of the word line; a tunneling strip on a top surface of the word line, the sidewall of the word line, a bottom surface of the word line, and the sidewalls of the dielectric layers; a semiconductor strip on the tunneling strip; a bit line contacting a sidewall of the semiconductor strip; and a source line contacting the sidewall of the semiconductor strip.