Patent ID: 8345465
Filing Date: 2013-01-01
Classification: G11C

Abstract:
1. A method of driving a variable resistance element that includes a metal oxide having a resistance value increased and decreased depending on application of electric pulses, the metal oxide comprising a first oxide layer and a second oxide layer which are stacked, the second oxide layer having an oxygen content percentage higher than an oxygen content percentage of the first oxide layer, said method comprising: performing a plurality of writing steps by applying a writing voltage pulse having a first polarity to the metal oxide, so as to change a resistance state of the metal oxide from high to low; and performing a plurality of erasing steps by applying an erasing voltage pulse having a second polarity to the metal oxide, so as to change the resistance state of the metal oxide from low to high, the second polarity being different from the first polarity, wherein |Vw |Ve the (N+1)-th writing step follows the M-th erasing step.