| 主权项 |
1. A forming method for a variable-resistance nonvolatile memory element, the forming method comprising:
(A) applying a first pulse voltage to the variable-resistance nonvolatile memory element in a first state, the first pulse voltage having a first polarity; and (B) executing at least once a sequence that includes
(b1) determining whether the variable-resistance nonvolatile memory element is in a second state, and(b2) continuously applying a second pulse voltage followed by a third pulse voltage to the variable-resistance nonvolatile memory element when the variable-resistance nonvolatile memory element is not in the second state, the second pulse voltage having a second polarity which is reverse to the first polarity, the third pulse voltage having the first polarity, wherein the variable-resistance nonvolatile memory element is irreversibly changeable from the first state to the second state, a resistance value of the variable-resistance nonvolatile memory element being larger in the first state than in the second state, the variable-resistance nonvolatile memory element has, in the second state, such a reversible resistance change characteristic that the resistance value decreases in response to application of a fourth pulse voltage and increases in response to application of a fifth pulse voltage, the fourth pulse voltage having the first polarity, the fifth pulse voltage having the second polarity, and an amplitude of the second pulse voltage is larger than an amplitude of the fifth pulse voltage. |
