Patent classifications
G11C11/2259
Analog Non-Volatile Memory Device Using Poly Ferrorelectric Film with Random Polarization Directions
A semiconductor device includes a ferroelectric field-effect transistor (FeFET), wherein the FeFET includes a substrate; a source region in the substrate; a drain region in the substrate; and a gate structure over the substrate and between the source region and the drain region. The gate structure includes a gate dielectric layer over the substrate; a ferroelectric film over the gate dielectric layer; and a gate electrode over the ferroelectric film.
Method of forming stacked ferroelectric planar capacitors in a memory bit-cell
A high-density low voltage ferroelectric (or paraelectric) memory bit-cell that includes a planar ferroelectric or paraelectric capacitor. The memory bit-cell comprises 1T1C configuration, where a plate-line is parallel to a word-line, or the plate-line is parallel to a bit-line. The memory bit-cell can be 1TnC, where ‘n’ is a number. In a 1TnC bit-cell, the capacitors are vertically stacked allowing for multiple values to be stored in a single bit-cell. The memory bit-cell can be multi-element FE gain bit-cell. In a multi-element FE gain bit-cell, data sensing is done with signal amplified by a gain transistor in the bit-cell. As such, higher storage density is realized using multi-element FE gain bit-cells. In some examples, the 1T1C, 1TnC, and multi-element FE gain bit-cells are multi-level bit-cells. To realize multi-level bit-cells, the capacitor is placed in a partially switched polarization state by applying different voltage levels or different time pulse widths at the same voltage level.
SELF-REFERENCE SENSING FOR MEMORY CELLS
Methods, systems, and apparatuses for self-referencing sensing schemes are described. A cell having two transistors, or other switching components, and one capacitor, such as a ferroelectric capacitor, may be sensed using a reference value that is specific to the cell. The cell may be read and sampled via one access line, and the cell may be used to generate a reference voltage and sampled via another access line. For instance, a first access line of a cell may be connected to one read voltage while a second access line of the cell is isolated from a voltage source; then the second access line may be connected to another read voltage while the first access line is isolate from a voltage source. The resulting voltages on the respective access lines may be compared to each other and a logic value of the cell determined from the comparison.
MEMORY ARRAY DECODING AND INTERCONNECTS
Methods and apparatuses for thin film transistors and related fabrication techniques are described. The thin film transistors may access two or more decks of memory cells disposed in a cross-point architecture. The fabrication techniques may use one or more patterns of vias formed at a top layer of a composite stack, which may facilitate building the thin film transistors within the composite stack while using a reduced number of processing steps. Different configurations of the thin film transistors may be built using the fabrication techniques by utilizing different groups of the vias. Further, circuits and components of a memory device (e.g., decoder circuitry, interconnects between aspects of one or more memory arrays) may be constructed using the thin film transistors as described herein along with related via-based fabrication techniques.
RESISTANCE NETWORK HAVING FOUR CONTACTS PER MEMORY CELL
A resistor network and an integrated circuit at least part of the resistor network may have at least two memory cells for storing in each case one resistance characteristic value. Each memory cell may have a first contact pair configured to provide an electrical resistance corresponding to the stored resistance characteristic value in at least one operating mode. First contacts of the respective first contact pair of the two memory cells are directly connected to one another and second contacts of the respective first contact pair of the two memory cells are electrically independent of one another. The memory cells may each have a second contact pair which is electrically independent of the first contact pair and which is arranged in such a way that the stored electrical resistance characteristic value of the respective memory cell can be reversibly changed by suitable electrical signals via this second contact pair.
Array Of Memory Cells
A method used in forming an array of memory cells comprises forming a vertical stack comprising transistor material directly above and directly against a first capacitor electrode material. A mask is used to subtractively etch both the transistor material and thereafter the first capacitor electrode material to form a plurality of pillars that individually comprise the transistor material and the first capacitor electrode material. Capacitors are formed that individually comprise the first capacitor electrode material of individual of the pillars. Vertical transistors are formed above the capacitors that individually comprise the transistor material of the individual pillars. Other aspects and embodiments are disclosed, including structure independent of method.
FERROELECTRIC MEMORY DEVICE USING BACK-END-OF-LINE (BEOL) THIN FILM ACCESS TRANSISTORS AND METHODS FOR FORMING THE SAME
A memory device includes metal interconnect structures embedded within dielectric material layers that overlie a top surface of a substrate, a thin film transistor embedded in a first dielectric material layer selected from the dielectric material layers, and is vertically spaced from the top surface of the substrate, and a ferroelectric memory cell embedded within the dielectric material layers. A first node of the ferroelectric memory cell is electrically connected to a node of the thin film transistor through a subset of the metal interconnect structures that is located above, and vertically spaced from, the top surface of the substrate.
Systems and methods for data relocation using a signal development cache
Methods, systems, and devices related to data relocation via a cache are described. In one example, a memory device in accordance with the described techniques may include a memory array, a sense amplifier array, and a signal development cache configured to store signals (e.g., cache signals, signal states) associated with logic states (e.g., memory states) that may be stored at the memory array (e.g., according to various read or write operations). In some cases, the memory device may transfer data from a first address of the memory array to the signal development cache. The memory device may transfer the data stored in the signal development cache to a second address of the memory array based on a parameter associated with the first address of the memory array satisfying a criterion for performing data relocation.
Memory array contact structures
A memory cell includes a transistor including a memory film extending along a word line; a channel layer extending along the memory film, wherein the memory film is between the channel layer and the word line; a source line extending along the memory film, wherein the memory film is between the source line and the word line; a first contact layer on the source line, wherein the first contact layer contacts the channel layer and the memory film; a bit line extending along the memory film, wherein the memory film is between the bit line and the word line; a second contact layer on the bit line, wherein the second contact layer contacts the channel layer and the memory film; and an isolation region between the source line and the bit line.
Access schemes for activity-based data protection in a memory device
Methods, systems, and devices for activity-based data protection in a memory device are described. In one example, a memory device may include a set memory sections each having memory cells configured to be selectively coupled with access lines of the respective memory section. A method of operating the memory device may include determining a quantity of access operations performed on a set of sections of a memory device, selecting at least one of the sections for a voltage adjustment operation based on the determined quantity of access operations, and performing the voltage adjustment operation on the selected section. The voltage adjustment operation may include applying an equal voltage to opposite terminals of the memory cells, which may allow built-up charge, such as leakage charge accumulating from access operations of the selected memory section, to dissipate from the memory cells of the selected section.