Abstract: The present invention discloses a mask set for compensating for a misalignment between the patterns and method of compensating for a misalignment between the patterns. A mask set of the present invention comprises a first mask consisted of a mask substrate on which a main pattern and a plurality of sub-patterns are formed, said sub-patterns formed at a side of the main pattern; a second mask consisted of a mask substrate on which a plurality of hole patterns are formed, the hole patterns corresponded to spaces between the main pattern and the sub-patterns of the first mask, respectively when the first and second mask are overlapped to each other; and a third mask consisted of mask substrate on which a plurality of bar patterns are formed, the bar patterns corresponded to the hole patterns of the second mask, respectively when the second and third mask are overlapped to each other.

Abstract: The present invention discloses a mask set for compensating for a misalignment between the patterns and method of compensating for a misalignment between the patterns. A mask set of the present invention comprises a first mask consisted of a mask substrate on which a main pattern and a plurality of sub-patterns are formed, said sub-patterns formed at a side of the main pattern; a second mask consisted of a mask substrate on which a plurality of hole patterns are formed, the hole patterns corresponded to spaces between the main pattern and the sub-patterns of the first mask, respectively when the first and second mask are overlapped to each other; and a third mask consisted of mask substrate on which a plurality of bar patterns are formed, the bar patterns corresponded to the hole patterns of the second mask, respectively when the second and third mask are overlapped to each other.

Abstract: The present invention discloses a mask set for compensating for a misalignment between the patterns and method of compensating for a misalignment between the patterns. A mask set of the present invention comprises a first mask consisted of a mask substrate on which a main pattern and a plurality of sub-patterns are formed, said sub-patterns formed at a side of the main pattern; a second mask consisted of a mask substrate on which a plurality of hole patterns are formed, the hole patterns corresponded to spaces between the main pattern and the sub-patterns of the first mask, respectively when the first and second mask are overlapped to each other; and a third mask consisted of mask substrate on which a plurality of bar patterns are formed, the bar patterns corresponded to the hole patterns of the second mask, respectively when the second and third mask are overlapped to each other.

Abstract: A voltage control circuit according to the present invention comprises a charge pump for generating a voltage depending on the clock signal inputted thereto; an oscillator for determining the cycle of the clock signal inputted to the charge pump; an adjusting unit for detecting the voltage generated from the charge pump to output an adjusting signal so that the oscillator can vary the cycle of the clock signal inputted to the charge pump.

Abstract: A flash memory which is electrically erasable programmable and has a negative voltage generator for data erasure. The negative voltage generator comprises a charge pump for pumping a negative charge, a regulator for regulating the level of an output voltage from the charge pump according to the level of a supply voltage, and a negative voltage supply for supplying a voltage of the level regulated by the regulator to a gate of a memory cell transistor. This construction of the negative voltage generator enables a data erase operation of the flash memory to be performed under the condition that an output voltage from the negative voltage supply is applied to the gate of the cell transistor, the supply voltage is applied to a source of the cell transistor and a drain of the cell transistor floats. Further, a sufficient amount of erase current is secured by the voltages applied to the source and gate of the cell transistor for the data erase operation.

Abstract: A voltage generation circuit of a semiconductor memory device has a charge pump circuit for supplying a voltage required to operate the semiconductor memory device; a voltage divide circuit having a plurality of capacitors and connected to the output of the charge pump circuit to divide the output of the charge pump circuit; an initialization means for discharging charges charged to the plurality of capacitors according to a reset signal; and a differential amplifier for controlling the charge pump circuit according to the result of comparison of the voltage divide circuit and a reference voltage.

Abstract: The present invention discloses a flash memory device, a first well and second well are formed in a substrate, a plurality of memory cell are formed in the second well and arranged in an array having a multiplicity of bit lines and word lines. Voltage is applied to the first well and second well, respectively, with time interval so that an over erasing of the memory cell and lowering of cycling characteristic can be prevented.

Abstract: The present invention provides a method for programming and erasing a plurality of flash memory cells simultaneously while the power consumptions for those operations are significantly reduced, and the method for programming a memory cell of a flash memory device, wherein the memory cell is formed on a P-well surrounded by an N-well of a semiconductor substrate, including the steps of: applying a negative voltage to a control gate of the memory cell; applying a positive voltage to a drain of the memory cell; applying a positive voltage to the P-well, wherein the voltage is the same as or lower than the voltage applied to the drain; applying a power supply voltage to the N-well; and leaving a source of the memory cell uncoupled, wherein the steps are performed either in sequence or at random.