Forming method of performing forming on variable resistance nonvolatile memory element, and variable resistance nonvolatile memory device

Abstract

When the variable resistance nonvolatile memory element having a first electrode, a second electrode, and a transition metal oxide layer sandwiched between the first electrode and the second electrode is in an initial state, the first electrode A first forming voltage is applied between the first electrode and the second electrode until the first formation of the first operable state reversibly transitioned between the high resistance state and the low resistance state occurs, between the first electrode and the second electrode. Applying a second forming voltage between the second electrodes until it changes to a resistance value lower than the resistance value of the low resistance state in the first operable state after the first formation. Formation of the variable resistance nonvolatile memory element proceeds until the second formation of the second operable state of the resistance state is performed.

Description

technical field [0001] The present invention relates to a formation (initialization) method for stably changing resistance of a resistance variable nonvolatile memory element whose resistance value is reversibly changed in accordance with an electrical signal, and a resistance variable nonvolatile memory having that function device. Background technique [0002] In recent years, resistance variable nonvolatile memory devices (hereinafter also simply referred to as "resistance variable elements") including memory cells constructed using resistance variable nonvolatile memory elements (hereinafter also simply referred to as "resistance variable elements") have been developed. "Non-volatile memory device".) research and development. The variable resistance element refers to an element that has a property of reversibly changing a resistance value according to an electric signal, and can further store data corresponding to the resistance value in a nonvolatile manner. [0003] ...

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Problems solved by technology

[0045] However, the above-mentioned conventional resistance variable semiconductor memory device has a problem that the formation voltage is not uniform for each resistance variable element constituting the memory cell array, or that the initial voltage applied to the resistance to transition to the state where the resistance change starts is The formation voltage of the change element becomes higher

In addition, although it will be described in detail later, it is clear that there is another problem in the formation method according to the related invention for solving such a problem that the cell current in the low-resistance state decreases (that is, the low resistance of the resistance variable element Insufficient resistance value in the state becomes low)

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