Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A memory array may be operated in a half density mode, in which a subset of the memory cells is designated as reference memory cells. Each reference memory cell may be paired to an active memory cell and may act as a reference signal when sensing the active memory cell. Each pair of active and reference memory cells may be connected to a single access line. Sense components (e.g., sense amplifiers) associated with reference memory cells may be deactivated in half density mode. The entire memory array may be operated in half density mode, or a portion of the array may operate in half density mode and the remainder of the array may operate in full density mode.

A memory device includes a plurality of memory cells. Each memory cell includes a multi-gate FeFET that has a first source/drain terminal, a second source/drain terminal, and a gate with a plurality of ferroelectric layers configured such that each of the ferroelectric layers has a respective unique switching E-field.

Methods, systems, and devices for a read algorithm for a memory device are described. When performing a read operation, the memory device may access a memory cell to retrieve a value stored by the memory cell. The memory device may compare a set of reference voltages with a signal output by the memory cell based on accessing the memory cell. Thus, the memory device may determine a set of candidate values stored by the memory cell, where each candidate value is associated with one of the reference voltages. The memory device may determine and output the value stored by the memory cell based on determining the set of candidate values. In some cases, the memory device may determine the value stored by the memory cell based on performing an error control operation on each of the set of candidate values to detect a quantity of errors within each candidate value.

One example provides a memory cell including a node, and a layer stack including a first electrode, a second electrode connected to the node, and a polarizable material layer disposed between the first and second electrodes and having at least two polarization states. A first transistor includes a source, a drain, and a gate terminal, with the gate terminal connected to the node. A selector element includes at least a first terminal and a second terminal, with the second terminal connected to the node.

Methods, systems, and apparatuses for self-referencing memory cells are described. A reference value for a cell may be created through multiple sense operations on the cell. The cell may be sensed several times and an average of at least two sensing operations may be used as a reference for another sense operation. For example, the cell may be sensed and the resulting charge stored at a capacitor. The cell may be biased to one state, sensed a second time, and the resulting charge stored at another capacitor. The cell may be biased to another state, sensed a third time, and the resulting charge stored to another capacitor. The values from the second and third sensing operations may be averaged and used as a reference value in a comparison with value of the first sensing operation to determine a logic state of the cell.

Techniques, systems, and devices for time-resolved access of memory cells in a memory array are described herein. During a sense portion of a read operation, a selected memory cell may be charged to a predetermined voltage level. A logic state stored on the selected memory cell may be identified based on a duration between the beginning of the charging and when selected memory cell reaches the predetermined voltage level. In some examples, time-varying signals may be used to indicate the logic state based on the duration of the charging. In some examples, the duration of the charging may be based on a polarization state of the selected memory cell, a dielectric charge state of the selected state, or both a polarization state and a dielectric charge state of the selected memory cell.

Provided are a three-dimensional semiconductor memory device, a method for manufacturing the same, a method for operating the same, and an electronic system including the same. The three-dimensional semiconductor memory device includes a substrate, a stack structure on the substrate, and vertical channel structures, which are provided in channel holes penetrating the stack structure, wherein each of the vertical channel structures includes a data storage pattern, a vertical channel pattern, a conductive pad, and a vertical semiconductor pattern, wherein the vertical channel pattern includes a first portion contacting the upper surface of the substrate and a second portion provided between the data storage pattern and the vertical semiconductor pattern, and wherein the vertical semiconductor pattern is spaced apart from the substrate with the first portion of the vertical channel pattern therebetween.

In an embodiment, a device includes: a first dielectric layer over a substrate; a word line over the first dielectric layer, the word line including a first main layer and a first glue layer, the first glue layer extending along a bottom surface, a top surface, and a first sidewall of the first main layer; a second dielectric layer over the word line; a first bit line extending through the second dielectric layer and the first dielectric layer; and a data storage strip disposed between the first bit line and the word line, the data storage strip extending along a second sidewall of the word line.

A memory device comprises an access transistor comprising a bitline and a wordline. A series of alternating plate lines and an insulating material is over the access transistor, the plate lines comprising an adhesion material on a top and a bottom thereof and a metal material in between the adhesion material, the metal material having one or more voids therein. Two or more ferroelectric capacitors is over the access transistor and through the series of alternating plate lines and an insulating material such that a first one of the ferroelectric capacitors is coupled to a first one of the plate lines and a second one of the ferroelectric capacitors is coupled to a second one of the plate lines, and wherein the two or more ferroelectric capacitors are each coupled to and controlled by the access transistor. A plurality of vias each land on a respective one of the plate lines, wherein the plurality of vias comprises a same metal material as the plate lines.

A ferroelectric recording medium includes an electrode layer, a ferroelectric recording layer, and a protection layer formed in this order on a substrate, wherein the ferroelectric recording layer includes a ferroelectric layer, and a lattice constant of a material constituting the ferroelectric layer and a lattice constant of a material constituting the electrode layer or the substrate are lattice-matched within a range of ±10%.