METHOD OF PROGRAMMING VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT
First Claim
1. A method of programming a variable resistance nonvolatile memory element, the method of programming reversibly changing, by applying a voltage pulse to the variable resistance nonvolatile memory element, a resistance state of the variable resistance nonvolatile memory element,wherein the variable resistance nonvolatile memory element includes:
- a first electrode;
a second electrode; and
an oxygen-deficient transition metal oxide layer provided between the first and second electrodes,the transition metal oxide layer includes;
a first transition metal oxide layer that is in contact with the first electrode; and
a second transition metal oxide layer that is in contact with the second electrode and has a degree of oxygen deficiency lower than a degree of oxygen deficiency of the first transition metal oxide layer, andafter the variable resistance nonvolatile memory element is manufactured and an initial breakdown voltage pulse having a predetermined amplitude is applied between the first and second electrodes, the variable resistance nonvolatile memory element has characteristics of (i) changing to a low resistance state when a low resistance writing voltage pulse for providing a negative electric potential to the second electrode with respect to the first electrode is applied, and (ii) changing to a high resistance state when a high resistance writing voltage pulse for providing a positive electric potential to the second electrode with respect to the first electrode is applied, the high resistance state being higher in resistance value than the low resistance state,the method of programming comprising,in the case where the variable resistance nonvolatile memory element cannot change to the low resistance state and remains in the high resistance state when the low resistance writing voltage pulse is applied to the variable resistance nonvolatile memory element,applying a recovery voltage pulse to the variable resistance nonvolatile memory element at least once, the recovery voltage pulse including;
a first recovery voltage pulse that has an amplitude greater than an amplitude of the high resistance writing voltage pulse and provides the positive electric potential to the second electrode with respect to the first electrode; and
a second recovery voltage pulse that follows the first recovery voltage pulse and provides the negative electric potential to the second electrode with respect to the first electrode.
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Accused Products
Abstract
A method of programming a variable resistance nonvolatile memory element that removes a defect in a resistance change, ensures an operation widow, and stably sustains a resistance change operation, the method including: applying, when the detect in the resistance change occurs in the variable resistance nonvolatile memory element, a recovery voltage pulse at least once to the variable resistance nonvolatile memory element, the recovery voltage pulse including: a first recovery voltage pulse that has an amplitude greater than amplitudes of a normal high resistance writing voltage pulse and a low resistance writing voltage pulse; and a second recovery voltage pulse that is the low resistance writing voltage pulse following the first recovery voltage pulse.
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Citations
14 Claims
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1. A method of programming a variable resistance nonvolatile memory element, the method of programming reversibly changing, by applying a voltage pulse to the variable resistance nonvolatile memory element, a resistance state of the variable resistance nonvolatile memory element,
wherein the variable resistance nonvolatile memory element includes: - a first electrode;
a second electrode; and
an oxygen-deficient transition metal oxide layer provided between the first and second electrodes,the transition metal oxide layer includes;
a first transition metal oxide layer that is in contact with the first electrode; and
a second transition metal oxide layer that is in contact with the second electrode and has a degree of oxygen deficiency lower than a degree of oxygen deficiency of the first transition metal oxide layer, andafter the variable resistance nonvolatile memory element is manufactured and an initial breakdown voltage pulse having a predetermined amplitude is applied between the first and second electrodes, the variable resistance nonvolatile memory element has characteristics of (i) changing to a low resistance state when a low resistance writing voltage pulse for providing a negative electric potential to the second electrode with respect to the first electrode is applied, and (ii) changing to a high resistance state when a high resistance writing voltage pulse for providing a positive electric potential to the second electrode with respect to the first electrode is applied, the high resistance state being higher in resistance value than the low resistance state, the method of programming comprising, in the case where the variable resistance nonvolatile memory element cannot change to the low resistance state and remains in the high resistance state when the low resistance writing voltage pulse is applied to the variable resistance nonvolatile memory element, applying a recovery voltage pulse to the variable resistance nonvolatile memory element at least once, the recovery voltage pulse including;
a first recovery voltage pulse that has an amplitude greater than an amplitude of the high resistance writing voltage pulse and provides the positive electric potential to the second electrode with respect to the first electrode; and
a second recovery voltage pulse that follows the first recovery voltage pulse and provides the negative electric potential to the second electrode with respect to the first electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- a first electrode;
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8. A variable resistance nonvolatile memory device comprising:
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a variable resistance nonvolatile memory element including;
a first electrode;
a second electrode; and
an oxygen-deficient transition metal oxide layer provided between the first and second electrodes; anda drive circuit, wherein the transition metal oxide layer includes;
a first transition metal oxide layer that is in contact with the first electrode; and
a second transition metal oxide layer that is in contact with the second electrode and has a degree of oxygen deficiency lower than a degree of degree of oxygen deficiency of the first transition metal oxide layer,after the variable resistance nonvolatile memory element is manufactured and an initial breakdown voltage pulse having a predetermined amplitude is applied between the first and second electrodes, the variable resistance nonvolatile memory element has characteristics of (i) changing to a low resistance state when a low resistance writing voltage pulse for providing a negative electric potential to the second electrode with respect to the first electrode is applied, and (ii) changing to a high resistance state when a high resistance writing voltage pulse for providing a positive electric potential to the second electrode with respect to the first electrode is applied, the high resistance state being higher in resistance value than the low resistance state, and in the case where the variable resistance nonvolatile memory element cannot change to the low resistance state and remains in the high resistance state when the low resistance writing voltage pulse is applied to the variable resistance nonvolatile memory element, the drive circuit applies a recovery voltage pulse to the variable resistance nonvolatile memory element at least once, the recovery voltage pulse including;
a first recovery voltage pulse that has an amplitude greater than an amplitude of the high resistance writing voltage pulse and provides the positive electric potential to the second electrode with respect to the first electrode; and
a second recovery voltage pulse that follows the first recovery voltage pulse and provides the negative electric potential to the second electrode with respect to the first electrode. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification