Patent ID: 9142289
Filing Date: 2015-09-22
Classification: G11C

Abstract:
1. A driving method for driving a variable resistance element including a first electrode, a second electrode, and a variable resistance layer interposed between the first electrode and the second electrode, the variable resistance layer having a stacked structure including: a first metal oxide layer comprising an oxide of a first metal; and a second metal oxide layer comprising an oxide of a second metal and having a lower oxygen deficiency than the first metal oxide layer, a resistance value of the variable resistance layer reversibly changing by oxygen ions migrating based on a voltage pulse applied between the first electrode and the second electrode, the driving method comprising: a low resistance write process in which a resistance state of the variable resistance layer is changed from a high resistance state to a low resistance state by applying a low resistance writing voltage pulse having a first polarity to the variable resistance layer; and a high resistance write process in which the resistance state of the variable resistance layer is changed from the low resistance state to the high resistance state by applying a high resistance writing voltage pulse having a second polarity different from the first polarity to the variable resistance layer, wherein the high resistance write process completes one change of the resistance state of the variable resistance layer to the high resistance state by applying at least a plurality of the high resistance writing voltage pulses to the variable resistance layer, the high resistance write process includes the steps of: (a) applying a first high resistance writing voltage pulse having a voltage value VH (b) applying a second high resistance writing voltage pulse having a voltage value VH