The total silicon area used by a plurality of high voltage transistors in an array of NAND cells is reduced by modifying the silicon area layout such that the size of the source and drain of each of the plurality of high voltage transistors is dependent on the maximum voltage to be applied to each of the source and drain for the respective one of the plurality of high voltage transistors.

According to one embodiment, a semiconductor memory device includes a memory cell array, a data storage circuit and a control circuit. The data storage circuit holds first data to be written into the memory cell and holds 1 bit data calculated from the first data. The control circuit writes the data of n bits into the memory cell in a first write operation and then executes a second write operation. The control circuit carries out the following control in the second write operation. It reads data stored in the memory cell in the first write operation. It restores the first data based on the data read from the memory cell and the 1 bit data held in the data storage circuit. It writes the restored first data into the memory cell.

A semiconductor device includes a memory device and a controller configured to perform an erase operation on the memory device, perform a correction operation for a threshold voltage of a deep-erased cell, and perform an erase verify operation by identifying whether threshold voltages of a plurality of cells of the memory device fall within a predefined range.

A memory device comprising: a plurality of memory blocks each including a plurality of word lines arranged between a first and second select line, a peripheral circuit performs an erase operation by applying an erase voltage to a source or drain line of a selected memory block, and a control logic controls, in a period in which the erase operation is performed, the peripheral circuit to: sequentially select the plurality of word lines included in the selected memory block at least one by one from a word line closest to the first and second select line to a word line farthest from the first and second select line, apply a first erase permission voltage to the selected word lines, and apply a second erase permission voltage, which have a higher potential level than the first erase permission voltage, to remaining word lines except the selected word lines.

A three-dimensional non-volatile memory includes memory blocks including layers. A data method for erasure verification of the three-dimensional non-volatile memory includes selecting a first layer from the layers on which an erase operation has been performed. The method also includes applying a first local verification voltage to a word line corresponding to the first layer to verify the erase operation on the first layer. When a full block erasure verification is performed on the memory blocks corresponding to the first layer, a voltage applied to the word line corresponding to the memory blocks is a global verification voltage, and the first local verification voltage is lower than the global verification voltage.

According to one embodiment, a memory system includes a nonvolatile semiconductor memory, and a controller. The semiconductor memory includes a memory cell, and a write circuit configured to write data to the memory cell by applying a program voltage to the memory cell and comparing a threshold voltage of the memory cell with a first reference voltage corresponding to the write data. The write circuit is configured to execute a first programming operation to obtain a value of a write parameter by comparing the threshold voltage with a second reference voltage different from the first reference voltage.

Control logic in a memory device cause a programming pulse to be applied to a set of wordlines including a first set of even-numbered wordlines corresponding to a first set of memory cells to be erased and a second set of odd-numbered wordlines corresponding to a second set of memory cells to be erased, where a set of electrons are injected into a first set of gate regions, a second set of gate regions, and a set of inter-cell regions of a charge trap (CT) layer of the memory device. The control logic executes a first erase cycle on the first set of even-numbered wordlines to remove a first subset of electrons from the first set of gate regions corresponding to the first set of even-numbered wordlines. The control logic executes a second erase cycle on the second set of odd-numbered wordlines to remove a second subset of electrons from the second set of gate regions corresponding to the second set of even-numbered wordlines.

To help reduce program disturbs in non-selected NAND strings of a non-volatile memory, a sub-block based boosting scheme in introduced. For a three dimensional NAND memory structure, in which the memory cells above a joint region form an upper sub-block and memory cells below the joint region form a lower sub-block, dummy word lines in the joint region act as select gates to allow boosting at the sub-block level when the lower block is being programmed in a reverse order.

A data writing method for a rewritable non-volatile memory module is provided. The method includes grouping physical erasing units of a rewritable non-volatile memory module at least into a first area and a second area, wherein the second area is programmed with a single-page programming mode and the first area is programmed with a multi-page programming mode. The method further includes receiving first data; and determining whether the number of a physical erasing unit having only part of physical programming units being programmed among the physical erasing units of the first area is less than a predetermined value, and if yes, writing the first data into the physical erasing units of the second area.

A memory system according to an embodiment includes a first bit line, a source line, a first word line, a second word line, a first memory pillar and a control circuit. The control circuit performs a first verify operation to first and second memory cells, a second verify operation to the first memory cell, a third verify operation to the second memory cell and a write operation or a read operation with a lower voltage in accordance with a request from an external device.