Recovery pulses to counter cumulative read disturb
Granted: April 30, 2024
Patent Number:
11972808
A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to word lines and disposed in memory holes organized in rows grouped in strings and configured to retain a threshold voltage. The memory cells are connected in series between a drain-side select gate transistor on a drain-side of each of the memory holes and a source-side select gate transistor on a source-side of each of the memory holes. A control means determines whether a downshift…
Ferroelectric devices including a single crystalline ferroelectric layer and method of making the same
Granted: April 30, 2024
Patent Number:
11973123
A semiconductor structure includes an active region including a source region, a drain region, and a channel region extending between the source region and the drain region, a gate stack, and a gate dielectric layer located between the gate stack and the active region. The gate stack includes an electrically conductive gate electrode and a single crystalline III-nitride ferroelectric plate located between the electrically conductive gate electrode and the gate dielectric layer, and an…
Non-volatile memory with one sided phased ramp down after program-verify
Granted: April 30, 2024
Patent Number:
11972819
In a non-volatile memory system that performs programming of selected memory cells (in coordination with pre-charging and boosting of channels for unselected memory cells) and program-verify to determine whether the programming was successful, the system transitions from program-verify to the next dose of programming by concurrently lowering a voltage applied to a selected word line and voltages applied to word lines on a first side of the selected word line at the conclusion of…
Refresh frequency-dependent system-level trimming of verify level offsets for non-volatile memory
Granted: April 30, 2024
Patent Number:
11972818
A memory apparatus and method of operation are provided. The apparatus includes memory cells each connected to word lines. The memory cells are disposed in strings and configured to retain a threshold voltage corresponding to data states. A control means is configured to apply verification pulses of program verify voltages each associated with one of the data states to selected ones of the word lines to determine whether the memory cells connected thereto have the threshold voltage above…
Post-write read techniques to improve programming reliability in a memory device
Granted: April 30, 2024
Patent Number:
11972815
The memory device includes a controller that is configured to program a plurality of memory cells of a selected word line in a plurality of programming loops and count the number of programming loops to complete programming. The controller is also configured to compare the number of programming loops to complete programming of the memory cells of the selected word line to at least one of a predetermined upper limit and a predetermined lower limit to determine if a plane containing the…
Verify techniques for current reduction in a memory device
Granted: April 30, 2024
Patent Number:
11972814
The memory device includes a plurality of memory cells, which include a first set of memory cells and a second set of memory cells. A controller is in communication with the memory cells. The controller is configured to, in a first programming pass and then a second programming pass, program the memory cells of the first and second sets to respective final threshold voltages associated with a plurality of programmed data states. The controller is further configured to, in the first…
Systems and methods for adapting sense time
Granted: April 30, 2024
Patent Number:
11972813
A memory device with adaptive sense time tables is disclosed. In order to maintain a desired (initial or preset) threshold voltage distribution, the sense time is adjusted as the program-erase cycle count increases. The program-erase cycle process tends to wear down memory cells, causing the QPW window to expand and the threshold voltage to widen. However, by adjusting (i.e., reducing) the sense time for increased program-erase cycles, the QPW window and the threshold voltage can be at…
Non-volatile memory with data refresh based on data states of adjacent memory cells
Granted: April 30, 2024
Patent Number:
11972812
A memory system identifies memory cells connected to a common word line that have had their threshold voltage unintentionally drift lower than programmed by determining whether memory cells meet two criteria: (1) the memory cells have threshold voltages within an offset of a read compare voltage of a data state; and (2) adjacent memory cells (connected to word lines that are adjacent to the common word line) are in one or more low data states. For those memory cells meeting the two…
Read pass voltage dependent recovery voltage setting between program and program verify
Granted: April 30, 2024
Patent Number:
11972810
A memory apparatus and method of operation are provided. The apparatus includes memory cells connected word lines. The memory cells are disposed in strings and configured to retain a threshold voltage. A control means is configured to apply a program voltage to selected ones of the word lines while applying pass voltages to unselected ones of the word lines and ramp down both the selected ones of the plurality of word lines and the unselected ones of the word lines to a recovery voltage…
Selective inhibit bitline voltage to cells with worse program disturb
Granted: April 30, 2024
Patent Number:
11972809
A non-volatile semiconductor memory device includes non-volatile storage elements and one or more control circuits in communication with the non-volatile storage elements. The one or more control circuits are configured to determine for a program iteration of a program operation on a word line whether a condition is met and in response to determining that the condition is met, identify one or more memory cells of the word line that are in an erased state that have a threshold voltage…
Current mirror circuits
Granted: April 30, 2024
Patent Number:
11971736
A circuit is provided that includes a first transistor having a first terminal, a second terminal and a third terminal, and a second transistor comprising a first terminal, a second terminal and a third terminal. The first terminal of the first transistor comprises an input terminal of the circuit, the second terminal of the first transistor is coupled to a power supply bus, and the first transistor conducts a first current. The first terminal of the first transistor comprises an output…
Charge pump current regulation during voltage ramp
Granted: April 30, 2024
Patent Number:
11972807
Technology is disclosed herein for a memory system that regulates charge pump current during a ramp up of the output voltage. The memory systems operates the charge pump in a current regulation mode while the charge pump output voltage ramps up. After the output voltage crosses a threshold voltage, the charge pump is operated in a voltage regulation mode in which the output voltage is regulated to a target output voltage. In one aspect, the memory system generates a random duty cycle…
Read techniques to reduce read errors in a memory device
Granted: April 30, 2024
Patent Number:
11972806
The memory device includes a memory block with a plurality of memory cells, which are programmed to multiple bits per memory cell, arranged in a plurality of word lines. Control circuitry is provided and is configured to read the memory cells of a selected word line. The control circuitry separates the memory cells of the selected word line into a first group of memory cells, which are located on a side of the word line are near a voltage driver, and a second group of memory cells, which…
Non-volatile memory with narrow and shallow erase
Granted: April 30, 2024
Patent Number:
11972805
In a non-volatile memory, to achieve a shallow and tight erased threshold voltage distribution, a process is performed that includes erasing a group of non-volatile memory cells, identifying a first set of the bit lines that are connected to non-volatile memory cells of the group that are erased past a lower limit for erased non-volatile memory cells and identifying a second set of the bit lines that are connected to non-volatile memory cells of the group that are not erased past the…
Techniques for checking vulnerability to cross-temperature read errors in a memory device
Granted: April 30, 2024
Patent Number:
11972804
The memory device includes a memory block with an array of memory cells. The memory device also includes control circuitry that is in communication with the memory cells. The control circuitry is configured to program a group of the memory cells in a programming operation that does not include verify to obtain a natural threshold voltage (nVt) distribution, calculate an nVt width of the nVt distribution, compare the nVt width to a threshold, and identify the memory block as being…
Word line zone dependent pre-charge voltage
Granted: April 30, 2024
Patent Number:
11972803
A memory device that uses different programming parameters base on the word line(s) to be programmed is described. The programming parameter PROGSRC_PCH provides a pre-charge voltage to physical word lines. In some instances, the PROGSRC_PCH voltage is decoupled, and a new PROGSRC_PCH represents an adjusted (e.g., increased) pre-charge voltage for a certain physical word line or word line zone (i.e., predetermined group of word lines). Using different PROGSRC_PCH voltages can limit or…
Program voltage dependent program source levels
Granted: April 30, 2024
Patent Number:
11972801
A non-volatile semiconductor memory device, described herein, comprises non-volatile storage elements and one or more control circuits in communication with the non-volatile storage elements. The one or more control circuits are configured to, during a program iteration of a program operation, determine whether a program voltage level of the program iteration exceeds a threshold program voltage level and in response to the determination, identify a set of voltage levels to apply to a…
Cross-point array refresh scheme
Granted: April 30, 2024
Patent Number:
11972787
Technology is disclosed herein for refreshing threshold switching selectors in programmable resistance memory cells in cross-point memory arrays. The Vt of the threshold switching selector may drift over time. The memory system resets the Vt of the threshold switching selectors with a selector refresh operation and uses a separate data refresh operation to refresh data in programmable resistance memory elements. The data refresh operation itself may also refresh the selector. However,…
On-the-fly compression scheme for soft bit data in non-volatile memory
Granted: April 30, 2024
Patent Number:
11971829
For a non-volatile memory that uses hard bit and a soft bit data in error correction operations, an on-the-fly compression scheme is used for the soft bit data. As soft bit data is transferred to a memory's input-output interface, the soft bit data is compressed prior to transmission to the an ECC engine memory controller, while hard bit data is transferred in un-compressed form.
Architecture and data path options for compression of soft bit data in non-volatile memories
Granted: April 30, 2024
Patent Number:
11971826
For a non-volatile memory that uses hard bit and a soft bit data in error correction operations, architectures are introduced for the compression of the soft bit data to reduce the amount of data transferred over the memory's input-output interface. For a memory device with multiple planes of memory cells, the internal global data bus is segmented and a data compression circuit associated with each segment. This allows soft bit data from a cache buffer of a plane using one segment to…
