Sandisk Patent Grants

Three-dimensional memory device and method of making thereof using double pitch word line formation

Granted: March 26, 2024
Patent Number: 11942429
A vertical repetition of multiple instances of a unit layer stack is formed over a substrate. The unit layer stack includes an insulating layer and a sacrificial material layer. Lateral recesses are formed by removing the sacrificial material layers selective to the insulating layers. Each lateral recess is sequentially fill with at least one conductive fill material and an insulating fill material, and vertically-extending portions of the at least one conductive fill material are…

Variable bit line bias for nonvolatile memory

Granted: March 26, 2024
Patent Number: 11942157
An apparatus is provided that includes a word line coupled to a word line driver circuit, bit lines, a plurality of non-volatile memory cells each coupled to the word line and a corresponding one of the bit lines, and a control circuit coupled to the word line and the bit lines. The control circuit is configured to program the memory cells by causing the word line driver to apply a program pulse to the word line, and biasing each bit line to a corresponding bit line voltage that has a…

Three-dimensional memory device containing self-aligned bit line contacts and methods for forming the same

Granted: March 19, 2024
Patent Number: 11935784
A vertical layer stack including a bit-line-level dielectric layer and an etch stop dielectric layer can be formed over an array region. Bit-line trenches are formed through the vertical layer stack. Bit-line-trench fill structures are formed in the bit-line trenches. Each of the bit-line-trench fill structures includes a stack of a bit line and a capping dielectric strip. At least one via-level dielectric layer can be formed over the vertical layer stack. A bit-line-contact via cavity…

Free flow data path architectures

Granted: March 19, 2024
Patent Number: 11935622
A data path architecture and corresponding method of operation are disclosed that permit a first-in-first out (FIFO) buffer to immediately flush data—including potentially invalid initial byte(s)—upon receipt of a high-speed clock signal, and according to which, a delay difference between a data path clock signal and a high-speed clock signal is compensated for at a controller side by, for example, adjusting RE latency to discard/ignore the initially invalid bytes rather than by…

Burst programming of a NAND flash cell

Granted: March 19, 2024
Patent Number: 11935599
A fast burst program sequence that reduces overall NAND flash programming time is disclosed. The burst program sequence includes maintaining a charge pump in an ON state and not fully discharging the WL/BLs at the conclusion of the programming phase of each program operation. As a result, the fast burst program sequence provides total program time savings over an existing cache program sequence by eliminating the full WL/BL discharge and charge pump reset that conventionally occurs after…

Dummy cell resistance tuning in NAND strings

Granted: March 19, 2024
Patent Number: 11935593
An apparatus includes a control circuit configured to connect to memory cells connected in series in NAND strings. Each NAND string includes a plurality of data memory cells coupled to a plurality of data word lines in series with a plurality of dummy memory cells connected to a plurality of dummy word lines. The control circuit configured to apply a first dummy word line voltage to one or more dummy word lines of the plurality of dummy word lines in a verify step of a program operation…

Pseudo multi-plane read methods and apparatus for non-volatile memory devices

Granted: March 19, 2024
Patent Number: 11935585
An apparatus includes a control circuit and a plurality of non-volatile memory cells arranged in a plane of a memory die. The plane includes a first word line including a first word line portion coupled to a corresponding first group of the non-volatile memory cells, and a second word line including a second word line portion coupled to a corresponding second group of the non-volatile memory cells, the second word line different from the first word line. The control circuit is configured…

Window program verify to reduce data latch usage in memory device

Granted: March 12, 2024
Patent Number: 11929125
Apparatuses and techniques are described for reducing the number of latches used in sense circuits for a memory device. The number of internal user data latches in a sense circuit is reduced by using an external data transfer latch to store a bit of user data, in place of an internal user data latch. The user data in the data transfer latches identifies a subset of the data states which are not prohibited from having a verify test. The subset is shifted as the program operation proceeds,…

Determining charge pump efficiency using clock edge counting

Granted: March 12, 2024
Patent Number: 11927635
A charge pump test configuration and corresponding method of operation are disclosed for determining charge pump efficiency without needing to obtain direct current measurements. A first number of clock edges (CEs) of a clock signal supplied to a first charge pump is determined over a period of time for a predetermined output current. The first charge pump is then connected with a charge pump under test (PUT) in a cascaded manner such that an output current of the first charge pump is…

Three-dimensional memory device including sense amplifiers having a common width and separation

Granted: March 5, 2024
Patent Number: 11925027
A semiconductor structure includes a memory array including first and second bit lines and a sense amplifier circuit. The sense amplifier circuit includes a first sense amplifier array containing first active sense amplifier transistors that each have an active region having a first width, where the first active sense amplifier transistors are electrically connected to the first bit lines, and a second sense amplifier array including second active sense amplifier transistors that each…

Three-dimensional memory device including dielectric rails for warpage reduction and method of making the same

Granted: March 5, 2024
Patent Number: 11923321
A memory die includes dielectric isolation rails embedded within a substrate semiconductor layer, laterally spaced apart along a first horizontal direction, and each laterally extending along a second horizontal direction that is perpendicular to the first horizontal direction, and alternating stacks of insulating layers and electrically conductive layers located over the substrate semiconductor layer. The alternating stacks are laterally spaced apart along the second horizontal…

Data retention reliability

Granted: March 5, 2024
Patent Number: 11923019
The present disclosure provides for improving data retention reliability. During a programming operation associated with a memory cell, after the memory cell passes verification of a first verification voltage level, a second verification voltage level can be applied to the memory cell. Based on a comparison of the voltage in the memory cell with the second verification voltage level, a bit line voltage may be applied. Based on the applied bit line voltage, fast bits associated with the…

Two-stage high speed level shifter

Granted: February 27, 2024
Patent Number: 11916549
Improved voltage level shifters are disclosed capable of achieving substantially higher data transfer speeds with reduced static current than existing cross-coupled voltage level shifters. The voltage level shifters disclosed herein include first stage that translates input voltage signals received from a core circuitry in a first voltage domain to intermediate output voltage signals an intermediate voltage domain, and second stage circuitry that translates the intermediate output…

Non-volatile memory with isolation latch shared between data latch groups

Granted: February 27, 2024
Patent Number: 11915769
A non-volatile memory device includes a control circuit configured to connect to a bit line that is connected to one or more non-volatile memory cells. The control circuit includes a first plurality of data latches connected to a first local data bus to store first program-verify pass/fail bits and a second plurality of data latches connected to a second local data bus to store second program-verify pass/fail bits for second non-volatile memory cells. The non-volatile memory device…

On-the-fly multiplexing scheme for compressed soft bit data in non-volatile memories

Granted: February 20, 2024
Patent Number: 11907545
For a non-volatile memory that uses hard bit and soft bit data in error correction operations, to reduce the amount of soft bit data that needs to be transferred from a memory to the controller and improve memory system performance, the soft bit data can be compressed before transfer. After the soft bit data is read and stored into the internal data latches associated with the sense amplifiers, it is compressed within these internal data latches. The compressed soft bit data can then be…

Persistent memory management

Granted: February 20, 2024
Patent Number: 11907200
Apparatuses, systems, methods, and computer program products are disclosed for persistent memory management. Persistent memory management may include replicating a persistent data structure in volatile memory buffers of at least two non-volatile storage devices. Persistent memory management may include preserving a snapshot copy of data in association with completion of a barrier operation for the data. Persistent memory management may include determining which interface of a plurality…

Positive TCO voltage to dummy select transistors in 3D memory

Granted: February 13, 2024
Patent Number: 11901007
Technology for applying a positive temperature coefficient (Tco) voltage to a control terminal of a dummy select transistor. The dummy select transistor resides on a NAND string having non-volatile memory cells and a regular select transistor. The dummy select transistor is typically ON (or conductive) during memory operations such as selected string program, read, and verify. In an aspect, the positive Tco voltage is applied to the control terminal of a dummy select transistor during a…

Bonded memory devices and methods of making the same

Granted: February 13, 2024
Patent Number: 11903218
At least a portion of a memory cell is formed over a first substrate and at least a portion of a steering element or word or bit line of the memory cell is formed over a second substrate. The at least a portion of the memory cell is bonded to at least a portion of a steering element or word or bit line. At least one of the first or second substrate may be removed after the bonding.

Use of data latches for compression of soft bit data in non-volatile memories

Granted: February 13, 2024
Patent Number: 11901019
For a non-volatile memory that uses hard bit and soft bit data in error correction operations, to reduce the amount of soft bit data that needs to be transferred from a memory to the controller and improve memory system performance, the soft bit data can be compressed before transfer. After the soft bit data is read and stored into the internal data latches associated with the sense amplifiers, it is compressed within these internal data latches. The compressed soft bit data can then be…

Fast open block erase in non-volatile memory structures

Granted: February 13, 2024
Patent Number: 11901016
A method for performing an erase operation of a partially programmed memory block of a non-volatile memory structure. The method comprises: (1) applying an erase voltage bias level to a channel region of the memory block, (2) applying a word line voltage level to all programmed word line(s) of the memory block, (3) applying a “float” condition to all unprogrammed word line(s) of the memory block, and (4) applying an erase verify operation to all word line(s) of the memory block,…