Method for driving nonvolatile storage element, and nonvolatile storage device

摘要

Provided is a method for driving a variable resistance nonvolatile storage element that can improve the information holding capability. The method includes: determining whether or not a current that flows through the nonvolatile storage element is larger than or equal to a first verify level IRL (Verify); determining whether or not a current that flows through the nonvolatile storage element is smaller than or equal to a second verify level IRH (Verify); and determining that the nonvolatile storage element is in the second resistance state when the current that flows through the nonvolatile storage element is smaller than a current reference level Iref, and determining that the nonvolatile storage element is in the first resistance state when the current is larger than the current reference level Iref, the current reference level Iref satisfying (IRL (Verify)+IRH (Verify))/2

主权项

1. A method for driving a variable resistance nonvolatile storage element including a first electrode, a second electrode, and a variable resistance layer disposed between the first electrode and the second electrode, the method comprising:
applying a first voltage between the first electrode and the second electrode to set a resistance state between the first electrode and the second electrode to a first resistance state, the first voltage having a first polarity; determining whether or not a current that flows through the nonvolatile storage element with application of a first determination voltage between the first electrode and the second electrode is larger than or equal to a first verify level IRL (Verify), after the applying of a first voltage; applying a second voltage between the first electrode and the second electrode to set the resistance state between the first electrode and the second electrode to a second resistance state, the second voltage having a second polarity different from the first polarity; determining whether or not a current that flows through the nonvolatile storage element with application of a second determination voltage between the first electrode and the second electrode is smaller than or equal to a second verify level IRH (Verify), after the applying of a second voltage; detecting a current that flows through the nonvolatile storage element with application of a detection voltage between the first electrode and the second electrode; and determining that the nonvolatile storage element is in the second resistance state when the current detected in the detecting is smaller than a current reference level Iref, and determining that the nonvolatile storage element is in the first resistance state when the current detected in the detecting is larger than the current reference level Iref, the current reference level Iref satisfying (IRL (Verify)+IRH (Verify))/2