NONVOLATILE MEMORY IN WHICH PROGRAM OPERATION IS OPTIMIZED BY CONTROLLING SOURCE POTENTIAL

PROBLEM TO BE SOLVED: To prevent occurrence of such trouble that program operation is slowed by drop of drain voltage of a cell transistor to be programmed caused by voltage drop of a bit line. SOLUTION: This nonvolatile memory is characterized in that a source potential of the selection cell transistor is controlled so as to be varied in accordance with distance between a circuit (10) generating program voltage applied to bit lines and a selection cell transistor to be programmed. In preferable embodiment, when distance between the selection cell transistor and the circuit (10) generating program voltage is a first distance, a source potential of the selection cell transistor is made to be a first potential, when it is a second distance being longer than the first distance, a source potential of the selection cell transistor is controlled to the second potential being lower than the first potential. Thereby, voltage between a drain and a source of the selection cell transistor to be programmed can be optimized and optimization of program operation can be realized.