FLASH MEMORY DEVICE HAVING A MULTI LEVEL CELL AND PROGRAMMING METHOD THEREOF

摘要

A flash memory device having a multi level cell and a programming method thereof are provided to improve operation speed and reliability by assuring distribution width of a threshold voltage for each data and gap margin of threshold voltage distribution. A memory cell array(410) includes a number of memory cell blocks. A high voltage generator(430) generates an operation voltage applied to word lines and bit lines of the memory cell block. A bulk voltage generation part(480) generates a bulk bias of positive voltage applied to a bulk of the memory cell block in order to increase a threshold voltage of memory cells included in the memory cell block. A row decoder(440) generates a block selection signal to select one memory cell block among the memory cell blocks. A switching part(450) transfers the operation voltage to word lines and select lines of the selected memory cell block according to the block selection signal.