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 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.

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 method for forming a semiconductor memory structure is provided. The method includes forming a stack over a substrate, and the stack includes first dielectric layers and second dielectric layers vertically alternately arranged. The method also includes forming first dielectric pillars through the stack, and etching the stack to form first trenches. Sidewalls of the first dielectric pillars are exposed from the first trenches. The method also includes removing the first dielectric pillars to form through holes, removing the second dielectric layers of the stack to form gaps between the first dielectric layers, and forming first conductive lines in the gaps.

In some embodiments, an integrated circuit (IC) device includes an active semiconductor layer, a circuitry formed within the active semiconductor layer, a region including conductive layers formed above the active semiconductor layer, and a memory module formed in the region. The memory device includes a three-dimensional array of memory cells, each adapted to store a weight value, and adapted to generate at each memory cell a signal indicative of a product between the stored weight value and an input signal applied to the memory cell. The memory module is further adapted to transmit the product signals from the memory cell simultaneously in the direction of the active semiconductor layer.

Thin-film Ferroelectric field-effect transistor (FeFET) may be organized as 3-dimensional NOR memory string arrays. Each 3-dimensional NOR memory string array includes a row of active stack each including a predetermined number of active strips each provided one on top of another and each being spaced apart from another by an isolation layer. Each active strip may include a shared source layer and a shared drain layer shared by the FeFETs provided along the active strip. Data storage in the active strip is provided by ferroelectric elements that can individually electrically set into one of two polarization states. FeFETs on separate active strips may be configured for read, programming or erase operations in parallel.

A semiconductor die comprises a first set of semiconductor devices disposed at a first location of the semiconductor die and a second set of semiconductor devices disposed at a second location of the semiconductor die different from the first location. Each of the first set of semiconductor devices have a first workfunction to cause each of the first set of semiconductor devices to store memory for a first time period. Moreover, each of the second set of semiconductor devices have a second workfunction that is higher greater than the first workfunction to cause each of the second set of semiconductor devices to store memory for a second time period greater than the first time period.

A semiconductor storage device according to an embodiment includes a substrate, a first word line, a second word line, a first channel, a first memory film, a second channel, a second memory film, a first insulating layer, a first source line, and a first drain line. The second word line is separated from the first word line in a second direction. The first channel is aligned with the first word line in a third direction. The second channel is aligned with the second word line in the third direction. The first insulating layer is positioned between the first word line and the second word line in the second direction and between the first channel and the second channel in the second direction. The first source line and first drain line extend in the second direction.