Abstract: A non-volatile semiconductor memory including at least one first gate electrode as a floating gate on a semiconductor substrate with intervention of a first insulating film as a tunnel oxide film; sidewall spacers on both sidewalls of the first gate electrode in a direction of a channel length; a bit line formed of an impurity diffusion region of a conductivity type different from the conductivity type of the semiconductor substrate in a surface layer of the semiconductor substrate by the side of the first gate electrode, wherein the bit line comprises a first bit line formed in self-alignment using the first gate electrode as a mask and a second bit line formed in self-alignment using the first gate electrode and the sidewall spacers as a mask.

Abstract: A semiconductor memory device having a virtual ground line type memory array structure includes a readout circuit for selecting a pair of selected bit lines connected to the source and the drain of a memory cell to be read, applying a predetermined voltage to between the paired selected bit lines, and sensing a memory cell current flowing through the memory cell to be read, and a counter potential generation circuit for generating from an intermediate node potential, which is higher than any level of the potential on the selected bit lines and supplied from an intermediate node on a current path for feeding the memory cell current in the readout circuit, a counter potential which varies in the same direction as of the intermediate node potential depending on the memory cell current so that its variation is greater than that of the intermediate node potential, wherein the counter potential is applied to an unselected bit line allocated next to one at a high level of the paired selected bit lines.

Abstract: A nonvolatile semiconductor memory having a memory cell comprises: a semiconductor substrate having a pair of trenches formed on a surface thereof; first electrodes formed in a pair of trenches through the intervention of a first insulating film, respectively; a second electrode formed on the semiconductor substrate between the trenches through the intervention of a second insulating film; and a third electrode formed on the second electrode through the intervention of a third insulating film.

Abstract: A nonvolatile semiconductor memory having a memory cell comprises: a semiconductor substrate having a pair of trenches formed on a surface thereof; first electrodes formed in a pair of trenches through the intervention of a first insulating film, respectively; a second electrode formed on the semiconductor substrate between the trenches through the intervention of a second insulating film; and a third electrode formed on the second electrode through the intervention of a third insulating film.

Abstract: A semiconductor memory device of the invention comprises a plurality of bit lines formed by implanting a second conductive-type impurity in a first conductive-type semiconductor substrate; a thick insulating film on the bit lines; a thin insulating film between the neighboring bit lines; and a plurality of word lines formed on the thick and thin insulating films so as to cross the bit lines, wherein each of the word lines includes a plurality of first conductors and a second conductor which electrically connects the first conductors in series, the respective first conductors are formed on the thin insulating film, the top face of the thickest portion of the thick insulating film is higher than the top face of the first conductors, and the film thickness of the thick insulating film is made thinner toward the end.

Abstract: A method of writing data into a non-volatile semiconductor memory having a plurality of memory cells in which a word line is shared by memory cells and a bit line is shared by adjacent memory cells, the method including writing the data into memory cells connected to the same word line sequentially from a memory cell at one end to a memory cell at another end.

Abstract: A semiconductor readout circuit reads out a potential of each of plural data lines by comparing the potential with a potential of a common reference data line, using a sense amplifier provided for each of the data lines. This semiconductor readout circuit has a current control circuit provided for each of the data lines. The current control circuit controls the potential of the corresponding one of the data lines so that a potential difference between the potential of the corresponding data line and the potential of the reference data line can be reduced based on an output as to the potential difference detected by the sense amplifier.

Abstract: A method of writing data into a non-volatile semiconductor memory having a plurality of memory cells in which a word line is shared by memory cells and a bit line is shared by adjacent memory cells, the method including writing the data into memory cells connected to the same word line sequentially from a memory cell at one end to a memory cell at another end.

Abstract: A nonvolatile semiconductor memory device, including: a group of memory cells formed in X and Y directions in and on a semiconductor substrate, the X and Y directions crossing each other, each memory cell including source and drain regions formed in the substrate, a first insulating film formed on a surface of the substrate between the source and drain regions, a floating gate formed on the first insulating film, and a control gate formed above the floating gate via a second insulating film; a plurality of wordlines each connected to the control gates of the memory cells in the X direction; a plurality of sub-bit lines, each sub-bit line connected to a predetermined number of source and drain regions of the memory cells in the Y direction; a plurality of main-bit lines extending in the Y direction, each main-bit line being connected to the sub-bit line in the Y direction, and a plurality of dielectric layers laminated on the sub-bit lines, wherein each main-bit line is formed on any one of the plurality of di

Abstract: A semiconductor memory device comprises: a plurality of memory elements; at least one bit line, wherein a memory operation is performed via at least a portion of the bit line with respect to at least one of the plurality of memory elements; and a load resistance regulating circuit for changing a resistance value to reduce or eliminate a difference in bit line load resistance depending on a position of the memory element.

Abstract: A nonvolatile semiconductor memory having a memory cell comprises: a semiconductor substrate having a pair of trenches formed on a surface thereof; first electrodes formed in a pair of trenches through the intervention of a first insulating film, respectively; a second electrode formed on the semiconductor substrate between the trenches through the intervention of a second insulating film; and a third electrode formed on the second electrode through the intervention of a third insulating film.

Abstract: A nonvolatile semiconductor memory device, including: a group of memory cells formed in X and Y directions in and on a semiconductor substrate, the X and Y directions crossing each other, each memory cell including source and drain regions formed in the substrate, a first insulating film formed on a surface of the substrate between the source and drain regions, a floating gate formed on the first insulating film, and a control gate formed above the floating gate via a second insulating film; a plurality of wordlines each connected to the control gates of the memory cells in the X direction; a plurality of sub-bit lines, each sub-bit line connected to a predetermined number of source and drain regions of the memory cells in the Y direction; a plurality of main-bit lines extending in the Y direction, each main-bit line being connected to the sub-bit line in the Y direction, and a plurality of dielectric layers laminated on the sub-bit lines, wherein each main-bit line is formed on any one of the plurality of di

Abstract: A control signal MBPRG is inputted to individual block decoders that constitute a block decoder section 37 of an ACT type flash memory. Then, the level of the control signal MBPRG is set to “H” to select all the blocks regardless of the contents of address signals a5 through a13, and one word line WL is selected from all the blocks by the addresses a0 through a4. By thus selecting one word line WL every block that is electrically separated by the select transistor and simultaneously applying a write voltage during the test to the same number of word lines WL as the number of blocks, the possible occurrence of a bad influence exerted on the other memory cells is prevented even when the memory cells in which a write operation during the test has been executed include a memory cell that has a negative threshold voltage.

Abstract: A non-volatile semiconductor memory including at least one first gate electrode as a floating gate on a semiconductor substrate with intervention of a first insulating film as a tunnel oxide film; sidewall spacers on both sidewalls of the first gate electrode in a direction of a channel length; a bit line formed of an impurity diffusion region of a conductivity type different from the conductivity type of the semiconductor substrate in a surface layer of the semiconductor substrate by the side of the first gate electrode, wherein the bit line comprises a first bit line formed in self-alignment using the first gate electrode as a mask and a second bit line formed in self-alignment using the first gate electrode and the sidewall spacers as a mask.

Abstract: A method of writing data into a non-volatile semiconductor memory having a plurality of memory cells in which a word line is shared by memory cells and a bit line is shared by adjacent memory cells, the method including writing the data into memory cells connected to the same word line sequentially from a memory cell at one end to a memory cell at another end.

Abstract: A control signal MBPRG is inputted to individual block decoders that constitute a block decoder section 37 of an ACT type flash memory. Then, the level of the control signal MBPRG is set to “H” to select all the blocks regardless of the contents of address signals a5 through a13, and one word line WL is selected from all the blocks by the addresses a0 through a4. By thus selecting one word line WL every block that is electrically separated by the select transistor and simultaneously applying a write voltage during the test to the same number of word lines WL as the number of blocks, the possible occurrence of a bad influence exerted on the other memory cells is prevented even when the memory cells in which a write operation during the test has been executed include a memory cell that has a negative threshold voltage.

Abstract: A nonvolatile semiconductor memory device has a cell which includes a drain diffusion region and a source diffusion region formed on a surface layer of a semiconductor substrate; a first insulating film formed between the source diffusion region and the drain diffusion region; a floating gate formed on the first insulating film; a second insulating film formed on the floating gate; a first control gate formed on the second insulating film; a third insulating film formed on the first control gate and a sidewall thereof and on a sidewall of the floating gate; and a second control gate formed on the first control gate with the third insulating film interposed therebetween.

Abstract: A nonvolatile semiconductor memory device comprises: a pair of impurity diffusion layers formed on a surface of a semiconductor substrate; two control gates formed on the semiconductor substrate through the intervention of a charge accumulating layer, the two control gates being provided between the pair of impurity diffusion layers and adjacent to each of the impurity diffusion layers; a word gate transistor including a word line formed on the semiconductor substrate through the intervention of a word gate insulating film between the control gates, wherein the two control gates and the word gate transistor are connected in series to form a unit cell.

Abstract: A control signal MBPRG is inputted to individual block decoders that constitute a block decoder section. 37 of an ACT type flash memory. Then, the level of the control signal MBPRG is set to “H” to select all the blocks regardless of the contents of address signals a5 through a13, and one word line WL is selected from all the blocks by the addresses a0 through a4. By thus selecting one word line WL every block that is electrically separated by the select transistor and simultaneously applying a write voltage during the test to the same number of word lines WL as the number of blocks, the possible occurrence of a bad influence exerted on the other memory cells is prevented even when the memory cells in which a write operation during the test has been executed include a memory cell that has a negative threshold voltage.

Abstract: A nonvolatile semiconductor memory including at least two cells each comprising: a floating gate formed on a semiconductor substrate with the intervention of a first insulating film; a split gate formed on the semiconductor substrate with the intervention of a second insulating film at a predetermined distance from the floating gate; a control gate formed at least on the floating gate with the intervention of a third insulating film; and an impurity diffusion layer formed in a surface layer of the semiconductor substrate and capacitively coupled with an edge of the floating gate on an opposite side to the split gate in the channel direction, wherein the floating gate and the split gate of one cell are alternately arranged with the floating gate and the split gate of another adjacent cell along the channel direction and the impurity diffusion layer of one cell is capacitively coupled with a split gate of another adjacent cell.