A test structure for 3D memory arrays and methods of forming the same are disclosed. In an embodiment, a memory array includes a first word line over a semiconductor substrate and extending in a first direction; a second word line over the first word line and extending in the first direction; a memory film contacting the first word line and the second word line; an oxide semiconductor (OS) layer contacting a first source line and a first bit line, the memory film being between the OS layer and each of the first word line and the second word line; and a test structure over the first word line and the second word line, the test structure including a first conductive line electrically coupling the first word line to the second word line, the first conductive line extending in the first direction.

An example apparatus may perform concurrent threshold voltage compensation in a memory array with distributed row redundancy. The example apparatus may include a memory cell array having a mat having a plurality of row sections that each include respective prime memory cell rows and a respective redundant memory cell row. The example apparatus may further include a row decoder configured to receive an access command and a prime row address. The row decoder may be configured to, in response to a determination that the prime row address matches a defective prime row address, concurrently initiate a threshold voltage compensation operation on both of a prime row of the respective plurality of prime rows of memory cells of a first row section of the plurality of row sections corresponding to the prime row address and the respective redundant row of a second row section of the plurality of row sections.

A memory apparatus comprising: a cell array comprising multiple first and second word lines, a fuse array configured to substitute a selection word line of the multiple first word lines with the multiple second word lines, a fail determination unit configured to determine, as a fail word line, a word line matched with a first condition during an access operation for the multiple first word lines and to determine a fail grade of the fail word line based on a second condition, an information storage unit configured to store a physical address, fail grade and access count of the fail word line as determination information for the fail word line, and a rupture operation unit configured to select the selection word line from the fail word lines based on a result of the analysis of the determination information, and perform rupturing the selection word line into the fuse array.

A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to one of a plurality of word lines and arranged in strings and configured to retain a threshold voltage corresponding to one of a plurality of memory states. A control circuit is coupled to the plurality of word lines and strings and is configured to erase the memory cells using a stripe erase operation in response to determining a cycle count is less than a predetermined cycle count maximum threshold. The control circuit is also configured to perform a dummy cycle operation in response to determining the cycle count is not less than the predetermined cycle count maximum threshold.

An apparatus includes one or more control circuits configured to connect to a plurality of non-volatile memory cells arranged along word lines. The one or more control circuits are configured to receive a plurality of encoded portions of data to be programmed in non-volatile memory cells of a target word line, each encoded portion of data encoded according to an Error Correction Code (ECC) encoding scheme, and arrange the plurality of encoded portions of data in a plurality of rows of data latches corresponding to a plurality of logical pages such that each encoded portion of data is distributed across two or more rows of data latches. The one or more control circuits are also configured to program the distributed encoded portions of data from the plurality of rows of data latches into non-volatile memory cells along a target word line.

A method of operating a controller includes randomly transmitting a first command to a non-volatile memory device upon a read request from a host; receiving first read data corresponding to the first command from the non-volatile memory device; determining whether the number of first error bits of the first read data is greater than a first reference value; determining whether the number of first error bits is greater than a second reference value, when the number of first error bits is not greater than the first reference value; storing a target wordline in a health buffer, when the number of first error bits is greater than the second reference value; periodically transmitting a second command to the non-volatile memory device; and receiving second read data corresponding to the second command from the non-volatile memory device.

Methods, systems, and devices for adjustable programming pulses for a multi-level cell are described. A memory device may modify a characteristic of a programming pulse for an intermediate logic state based on a metric of reliability of associated memory cells. The modified characteristic may increase a read window and reverse a movement of a shifted threshold voltage distribution (e.g., by moving the threshold voltage distribution farther from one or more other voltage distributions). The metric of reliability may be determined by performing test writes may be a quantity of cycles of use for the memory cells, a bit error rate, and/or a quantity of reads of the first state. The information associated with the modified second pulse may be stored in fuses or memory cells, or may be implemented by a memory device controller or circuitry of the memory device.

A row decoder located on one side of a memory array selectively drives word lines in response to a row address. A word line fault detection circuit located on an opposite side of the first memory array operates to detect an open word line fault between the opposed sides of the memory array. The word line fault detection circuit includes a first clamp circuit that operates to clamp the word lines to ground. An encoder circuit encodes signals on the word lines to generate an encoded address. The encoded address is compared to the row address by a comparator circuit which sets an error flag indicating the open word line fault has been detected if the encoded address does not match the row address.

Embodiments of the present disclosure provide a method and an apparatus of testing a word line. After repair of a memory array is completed, if a target word line in a failure state exists in the memory array, a second numerical value is written into the target word line, and then it is determined, according to a numerical value outputted by each word line in the memory array, whether there are at least two word lines in an on-state in the memory array; if there are at least two word lines in an on-state simultaneously in the memory array, a current value generated by the target word line in an on-to-off process is detected; when the current value generated by the target word line in the on-to-off process is greater than a preset current threshold, it is determined that the target word line has a repair fault.

A data storage device including a memory device and a memory controller is disclosed. The memory controller including a super block includes a parity controller in communication with a memory device including a plurality of pages and configured to generate a first parity using data to be written to a first group of pages among the plurality of pages, and generate a second parity using data to be written to a second group of pages among the plurality of pages, a write operation controller configured to control the memory device to store the first parity and the second parity, and an error correction circuitry coupled to apply the first parity and the second parity to correct at least one of the plurality of pages arranged to belong to the first group of pages and the second group of pages.