Abstract: A memory device includes a plurality of memory cell transistors, a word line electrically connected to gates of the memory cell transistors, and a control circuit configured to perform programming of the memory cell transistors to a plurality of different threshold voltage ranges in a plurality of loops, each loop including a program operation and a program verification. The different threshold voltage ranges include a first threshold voltage range and a second threshold voltage range that is at a higher voltage than the first threshold voltage range. Further, during the program operation, the control circuit applies a program voltage to the word line, the program voltage increasing for each subsequent loop, an amount of increase of the program voltage when programming to the second threshold voltage range being set in accordance with a number of loops required to complete programming to the first threshold voltage range.

Abstract: 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.

Abstract: 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.

Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.

Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.

Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit configured to repeat a program operation and a verify operation. The control circuit performs a first verify operation of sensing whether threshold voltages of selected memory cells are greater than or equal to a first threshold voltage, and a second verify operation of sensing whether the threshold voltages of the selected memory cells are greater than or equal to a second threshold voltage (first threshold voltage<second threshold voltage), and the control circuit changes a charge voltage for the bit lines between the first verify operation and the second verify operation.

Abstract: 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.

Abstract: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: an erase operation to apply an erase pulse voltage to a memory cell for data erase, an erase verify operation to verify whether data erase is completed, and a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage.

Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.

Abstract: 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.

Abstract: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: an erase operation to apply an erase pulse voltage to a memory cell for data erase, an erase verify operation to verify whether data erase is completed, and a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage.

Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.

Abstract: A nonvolatile semiconductor memory device according to an embodiment includes: a memory cell array configured having NAND strings arranged therein; a plurality of word lines; a plurality of bit lines; a source line; and a control circuit configured to apply a verify voltage to a selected word line, apply a read pass voltage that renders conductive an unselected memory cell regardless of cell data to an unselected word line, and apply a bit line voltage of a certain value to a selected bit line, thereby executing a write verify operation that determines whether a selected memory cell has a desired threshold voltage or not. The control circuit is configured capable of changing a voltage value of the bit line voltage based on a position of the selected word line among the plurality of word lines relative to the NAND string.

Abstract: According to one embodiment, a semiconductor memory includes memory cells, word lines connected to gate of memory cells arranged in a row direction, a control circuit which controls the operation of the memory cells. During k-level data writing to a selected cell, the control circuit applies the corrected unselect voltage in accordance with the result of the reading of data from the unselected cell connected to the adjacent word line to the adjacent word line and applies a read voltage to the selected word line to read (k?1)-level data from the selected cell, and the control circuit writes data to the selected cell in accordance with the read (k?1)-level and the k-level data to be written.

Abstract: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: an erase operation to apply an erase pulse voltage to a memory cell for data erase, an erase verify operation to verify whether data erase is completed, and a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage.

Abstract: 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.

Abstract: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: an erase operation to apply an erase pulse voltage to a memory cell for data erase, an erase verify operation to verify whether data erase is completed, and a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage.

Abstract: 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.

Abstract: The disclosure describes a semiconductor memory device including a memory cell array and a control circuit. The memory cell array comprises a plurality of memory cells that each include a control gate and a charge accumulation layer and that each are configured to have a threshold set to be included in any of a plurality of threshold distributions, the memory cell being connected between a bit line and a source line. The control circuit, in at least one of a write verify operation and a read operation on a selected memory cell, applies to the control gate a control gate voltage to determine the threshold of the selected memory cell, the control gate voltage having a plurality of values respectively corresponded to the plurality of threshold distributions, and sets a voltage between the bit line and the source line based on the control gate voltage.

Abstract: A non-volatile semiconductor memory device according to one embodiment includes: a cell array; and a data writing unit that repeatedly executes a write loop including a programming operation of applying a program voltage to a selected word line and a passage voltage to non-selected word lines during writing of data, in which, when a difference between the passage voltage used in an n-th write loop and the passage voltage used in an n+1-th write loop is expressed as ?Vn and when a condition of L<M (L and M are integers) is satisfied, the data writing unit executes the write loop using the passage voltage where ?V(L?1)<?VL, ?VL??V(M?1), and ?V(M?1)<?VM.