A non-volatile memory system erasing groups of connected memory cells separately performs erase verify for memory cells connected to even word lines to generate even results and erase verify for memory cells connected to odd word lines to generate odd results. The even results and the odd results are used to determine if the erase verify process indicates that the erasing has successful completed. In addition, for each group of connected memory cells, a last even result for the group is compared to a last odd result for the group. Even if the erase verify indicated that the erasing has successfully completed, the system may determine that the erasing failed (i.e. due to a defect) if the number of groups of connected memory cells that have the last even result different than the last odd result is greater than a limit.

Apparatuses and techniques are described for controlling a bit line pre-charge voltage in a program operation based on a number of bits per cell, with a goal to reduce peak current consumption. In one aspect, the ramp up of a bit line voltage to an inhibit level is optimized according to the number of bits per cell. The ramp up can involve increasing the bit line voltage from an initial level to a target voltage at a regulated rate, then increasing the bit line voltage from the target voltage to a final voltage at an unregulated rate. In one approach, the regulated ramp rate is less for single-level cell programming compared to multi-level cell programming. The target voltage can also be optimized based on the number of bis per cell.

The present disclosure provides a memory apparatus and a method for accessing a 3D vertical memory array. The 3D vertical memory array comprises word lines organized in planes separated from each other by insulating material, bit lines perpendicular to the word line planes, memory cells coupled between a respective word line and a respective bit line. The apparatus also comprises a controller configured to select multiple word lines, select multiple bit lines, and simultaneously access multiple memory cells, with each memory cell at a crossing of a selected word line and a selected bit line. The method comprises selecting a multiple word lines, selecting multiple bit lines and simultaneously accessing multiple memory cells, with each memory cell at a crossing of a selected word line of the selected multiple word lines and a selected bit line of the selected multiple bit lines. A method of manufacturing a 3D vertical memory array is also described.

A memory circuit includes a plurality of bitcells coupled to a plurality of bitlines, a plurality of wordlines, a plurality of source lines, and a control line. A first of the bitcells and a second of the bitcells are coupled to a first of the bitlines. The first bitcell is coupled to a first of the source lines. The second bitcell is coupled to a second of the source lines. The first source line is different from the second source line.

Various embodiments of high voltage generation circuits, high voltage operational amplifiers, adaptive high voltage supplies, adjustable high voltage incrementor, adjustable reference supplies, and reference circuits are disclosed. These circuits optionally can be used for programming a non-volatile memory cell in an analog neural memory to store one of many possible values.

A variety of applications can include memory devices designed to provide stabilization of selector devices in a memory array of the memory device. A selector stabilizer pulse can be applied to a selector device of a string of the memory array and to a memory cell of multiple memory cells of the string with the memory cell being adjacent to the selector device in the string. The selector stabilizer pulse can be applied directly following an erase operation to the string to stabilize the threshold voltage of the selector device. The selector stabilizer pulse can be applied as part of the erase algorithm of the memory device. Additional devices, systems, and methods are discussed.

A non-volatile memory device is provided. The memory device includes: word lines stacked on a substrate; a string select lines on the word lines, the string select lines being spaced apart from each other in a first horizontal direction and extending in a second horizontal direction; and a memory cell array including memory blocks, each of which includes memory cells connected to the word lines and the string select lines. The string select lines include a first string select line, and a second string select line which is farther from a word line cut region than the first string select line, and a program operation performed on second memory cells connected to a selected word line and the second string select line is performed before a program operation performed on first memory cells connected to the selected word line and the first string select line.

Described are systems and methods for reducing maximum programming voltage in memory programming operations. An example memory device comprises: a memory array comprising a plurality of memory cells electrically coupled to a plurality of wordlines and a plurality of bitlines; and a controller coupled to the memory array, the controller to perform operations comprising: identifying one or more memory cells for performing a memory programming operation, wherein the memory cells are electrically coupled to a target wordline and one or more target bitlines; causing drain-side select gates and source-side select gates of the memory array to be turned off; causing unselected wordlines of the memory array to discharge to a predefined voltage level; and causing one or more programming voltage pulses to be applied to the target wordline.

According to one embodiment, a semiconductor memory device includes a first string unit including a first memory string including a first selection transistor and a first memory cell coupled to the first selection transistor, a second string unit including a second memory string including a second selection transistor and a second memory cell coupled to the second selection transistor, a first select gate line, a second select gate line, a first bit line, a second bit line, and a first word line. Both of the first select gate line and the second select gate line are selected in a first read operation. The first select gate line is selected and the second select gate line is not selected in a second read operation.

A semiconductor well of a non-volatile memory houses memory cells. The memory cells each have a floating gate and a control gate. Erasing of the memory cells includes biasing the semiconductor well with a first erase voltage having an absolute value greater than a breakdown voltage level of bipolar junctions of a control gate switching circuit of the memory. An absolute value of the first erase voltage is based on a comparison of a value of an indication of wear of the memory cells to a wear threshold value.