Sensing devices might include a first voltage node configured to receive a first voltage level, a second voltage node configured to receive a second voltage level lower than the first voltage level, a p-type field-effect transistor (pFET) selectively connected to a data line, and a sense node selectively connected to the pFET. The pFET might be connected between the first voltage node and the data line, between the second voltage node and the data line, and between the first voltage node and the data line. Memories might have controllers configured to cause the memories to determine whether a memory cell has an intended threshold voltage using similar sensing devices.

A semiconductor memory device includes a memory cell array, a peripheral circuit, and a control logic. The memory cell array includes a plurality of memory cells. The peripheral circuit performs a program operation on selected memory cells among the plurality of memory cells. The control logic controls the program operation of the peripheral circuit. The program operation includes a plurality of program loops. The control logic is configured to control the peripheral circuit to apply a program voltage to a select word line that is connected to the selected memory cells, apply a first under drive voltage that is determined based on at least one verify voltage to the select word line, and apply the at least one verify voltage to the select word line in each of the plurality of program loops. The first under drive voltage is at a lower voltage level than the at least one verify voltage.

Apparatus and methods are described to reduce program disturb for a memory string with a partial select gate drain, which is partially cut by a shallow trench. The memory string with a partial select gate drain is linked with a neighboring full select gate drain that during its programming can cause a program disturb in the memory string with a partial select gate drain. The bias voltage applied to the selected full select gate drain can be controlled from a high state for low memory program states to a lower state for the high memory program states. The high data states may cause program disturb. The reduction in the bias voltage can match a reduction in the bias voltage applied to the bit lines to reduce the program disturb while providing adequate signal to program the high states on the memory string of the full select gate drain.

In a non-volatile memory, a block of NAND strings is divided into sub-blocks by etching the select gate layers between sub-blocks. This results in a subset of NAND strings (e.g., at the border of the sub-blocks) having select gates that are partially etched such that the partially etched select gates are partially shaped as compared to the select gates of NAND strings that have not been etched. Host data is programmed to non-volatile memory cells that are connected to an edge word line and are on NAND strings having a complete shaped select gate. Host data is also programmed to non-volatile memory cells that are connected to non-edge word lines. However, host data is not programmed to non-volatile memory cells that are connected to the edge word line and are on NAND strings having a partial shaped select gate.

A nonvolatile semiconductor memory device includes a control circuit configured to control a soft program operation of setting nonvolatile memory cells to a first threshold voltage distribution state of the nonvolatile memory cells. When a characteristic of the nonvolatile memory cells is in a first state, the control circuit executes the soft program operation by applying a first voltage for setting the nonvolatile memory cells to the first threshold voltage distribution state to first word lines, and applying a second voltage higher than the first voltage to a second word line. When the characteristic of the nonvolatile memory cells is in a second state, the control circuit executes the soft program operation by applying a third voltage equal to or lower than the first voltage to the first word lines and applying a fourth voltage lower than the second voltage to the second word line.

A memory system includes a nonvolatile memory which comprises a plurality of memory cells capable of storing 4-bit data represented by first to fourth bits by sixteen threshold regions, and a memory controller configured to cause the nonvolatile memory to execute a first program for writing data of the first bit, the second bit, and the fourth bit and then causes the nonvolatile memory to execute a second program for writing data of the third bit. In fifteen boundaries existing between adjacent threshold regions among the first to sixteenth threshold regions, a maximum value of the number of first boundaries used for determining a value of the data of the first bit, the number of second boundaries used for determining a value of the data of the second bit, the number of third boundaries used for determining a value of the data of the third bit.

The present disclosure provides a method of data protection for a three-dimensional NAND memory. The method includes programming a memory cell of the 3D NAND memory according to programming data; and backing up a portion of the programming data associated with the memory cell in response to a program loop count (PLC) that is larger than a threshold value, where the PLC tracks a repeated number of the programming of the memory cell. A previous PLC can be set as the threshold value, where the previous PLC was used by a previous programming operation and was collected after the memory cell was programmed successfully to a previous target logic state.

Apparatus might include an array of memory cells comprising a plurality of strings of series-connected memory cells and a controller for access of the array of memory cells, wherein the controller is configured to cause the apparatus to perform a sense operation on a selected memory cell of a string of series-connected memory cells, and to discharge access lines connected to the string of series-connected memory cells in a defined manner following the sense operation.

When programming and verifying a memory device which includes a plurality of memory cells and a plurality of word lines, a first coarse programming is first performed on a first memory cell among the plurality of memory cells which is controlled by a first word line among the plurality of word lines, and then a second coarse programming is performed on a second memory cell among the plurality of memory cells which is controlled by a second word line among the plurality of word lines. Next, a first coarse verify current is used for determining whether the first memory cell passes a coarse verification and a second coarse verify current is used for determining whether the second memory cell passes a second coarse verification, wherein the second coarse verify current is smaller than the first coarse verify current.

A memory device includes a plurality of memory cells arranged in a plurality of rows and a plurality of strings. A method of programming the memory device includes programming a first row of the memory cells. The method also includes, after programing the first row of the memory cells, programming a second row of the memory cells. The second row is adjacent to the first row in a first string direction. The method further includes, after programming the second row of the memory cells, programming a third row of the memory cells. The third row is two rows apart from the second row in a second string direction opposite to the first string direction.