Flash memory device and program method of flash memory device using different voltages

A program method of a memory device including a plurality of memory strings, comprising:

• applying a first voltage to at least one memory string of the memory strings to be programmed;
• applying a second voltage to at least one memory string of the memory strings to be program-inhibited;
• applying a pass voltage to a plurality of word lines connected to the memory strings
• applying a local voltage to at least one word line of the plurality of word lines supplied with the pass voltage
• applying a program voltage to a selected word line of the plurality of word lines while applying the local voltage to at least one word line.

A flash memory device, comprising:

• a memory cell array comprising a plurality of memory cells coupled with a plurality of bit lines and a plurality of word lines;
• a column selector circuit configured to control a voltage applied to a selected bit line among the plurality of bit lines and to control a voltage applied to an unselected bit line among the plurality of bit lines, on the basis of data to be written;
• a control circuit configured to control a generation and application of a plurality of high voltages to the memory cell array;
• a high voltage generator circuit configured to generate the plurality of high voltages in response to the control circuit, the plurality of high voltages comprising a program voltage, a pass voltage which is lower than the program voltage, and a local voltage which is lower than the pass voltage and higher than or equal to a ground voltage;
• and
• a row selector circuit configured to apply the plurality of high voltages to the memory cell array in response to the control circuit,
• wherein the row selector circuit is configured to apply the pass voltage to the plurality of word lines to boost a channel voltage, to apply the local voltage to at least one word line among the plurality of word lines after the boosted channel voltage connected to the selected bit line among the plurality of bit lines is discharged, and then to apply the program voltage to a selected word line.