Nonvolatile memory element and method of manufacturing the same

A method of manufacturing a nonvolatile memory element including:

• a first electrode;
• a second electrode;
• and
• a variable resistance layer that is interposed between the first electrode and the second electrode and in which a resistance value thereof changes into at least two different resistance states,
• wherein the variable resistance layer possesses a stacked structure having a first metal oxide layer containing Hf and O, and a second metal oxide layer that is provided between the first metal oxide layer and at least one of the first electrode and the second electrode and contains Al and O,
• wherein a step of forming the variable resistance layer includes:
• forming the first metal oxide layer;
• and
• forming the second metal oxide layer,
• wherein the forming of the first metal oxide layer has a first magnetron sputtering step, under a mixed atmosphere of a reactive gas containing oxygen and an inert gas, of using hafnium as a metal target and setting a mixing ratio of the reactive gas and the inert gas so that a molar ratio of Hf and O (an O/Hf ratio) satisfies a range of 0.30 to 1.90,
• wherein the forming of the second metal oxide layer has a second magnetron sputtering step, under a mixed atmosphere of a reactive gas containing oxygen and an inert gas, of using aluminum as a metal target and setting a mixing ratio of the reactive gas and the inert gas so that a molar ratio of Al and O (an O/Al ratio) satisfies a range of 1.0 to 2.2,
• wherein the first electrode and the second electrode are made of a titanium nitride film,
• wherein each of a step of forming the first electrode and a step of forming the second electrode is a step of subjecting a Ti target to magnetron sputtering under a mixed atmosphere of a reactive gas containing nitrogen and an inert gas, and
• wherein in each of the step of forming the first electrode and the step of forming the second electrode, a mixing ratio of the nitrogen gas and the inert gas is set so that a molar ratio of Ti and N in the titanium nitride film is 1.15 or more, and that crystal orientation X being a ratio of (200) peak intensity and (111) peak intensity (C(200)/C(111)) in an X-ray diffraction spectrum of the titanium nitride film satisfies the range of 1.2<X.