Method of manufacturing resistance change layer using irradiation of electron beam and resistive random access memory device using the same
Methods of manufacturing a resistance change layer and a resistive random access memory device are provided. The method of manufacturing a resistance change layer includes forming a preliminary resistance change layer including an oxide semiconductor material on a substrate and irradiating the preliminary resistance change layer with an electron beam to a predetermined depth. On a path along which the electron beam is irradiated, a composition ratio of the resistance change layer changes in a direction in which a density of oxygen vacancies of the oxide semiconductor material increases. Accordingly, the composition ratio of a resistance change layer is easily controlled using electron beam irradiation. In addition, since interfacial surface roughness and internal defect structures of an oxide semiconductor are controlled by electron beam irradiation, a resistance change ratio is improved and thereby device characteristics can be improved.
1. A method of manufacturing a resistance change layer, comprising:
forming a preliminary resistance change layer including an oxide semiconductor material on a substrate; and
irradiating the preliminary resistance change layer with an electron beam to a predetermined depth to form a resistance change layer,
wherein, on a path along which the electron beam is irradiated, a composition ratio of the resistance change layer changes in a direction in which a density of oxygen vacancies of the oxide semiconductor material increases.
2. The method of claim 1 , wherein a quantum dot is included inside of the preliminary resistance change layer.
3. The method of claim 2 , wherein the forming of the preliminary resistance change layer comprises:
forming a first preliminary resistance change layer including an oxide semiconductor on the substrate;
forming a quantum dot on the first preliminary resistance change layer; and
forming a second preliminary resistance change layer including an oxide semiconductor on the first preliminary resistance change layer on which the quantum dot is formed.
4. The method of claim 3 , wherein the first preliminary resistance change layer includes a first oxide semiconductor layer and a first oxygen-deficient oxide semiconductor layer disposed on the first oxide semiconductor layer,
wherein the second preliminary resistance change layer includes a second oxygen-deficient oxide semiconductor layer and a second oxide semiconductor layer disposed on the second oxygen-deficient oxide semiconductor layer.
5. The method of claim 3 , wherein while the second preliminary resistance change layer is formed on the first preliminary resistance change layer, the quantum dot has a core-shell structure.
6. The method of claim 2 , wherein the irradiating of the preliminary resistance change layer with the electron beam to a predetermined depth is performed in such a way that the electron beam is irradiated to a top of an area in which the quantum dot is located.
7. A method of manufacturing a resistive random access memory device, comprising:
forming a first electrode on a substrate;
forming a first resistance change layer including an oxide semiconductor material on the first electrode;
forming a quantum dot on the first resistance change layer;
forming a second resistance change layer including an oxide semiconductor material on the first resistance change layer on which the quantum dot is formed;
irradiating the second resistance change layer with an electron beam to a predetermined depth; and
forming a second electrode on the second resistance change layer,
wherein a dislocation density of the second resistance change layer is decreased by irradiating the second resistance change layer with the electron beam.
8. The method of claim 7 , wherein the irradiating of the second resistance change layer with the electron beam to the predetermined depth is performed in such a way that the electron beam is irradiated to a top of an area in which the quantum dot is located.
9. The method of claim 7 , wherein the electron beam is irradiated with an energy of about 0.01 MeV to 0.2 MeV at a dose of about 1×10 14 e/cm 2 to 1×10 17 e/cm 2 .
10. The method of claim 7 , wherein, on a path along which the electron beam is irradiated, a composition ratio of the second resistance change layer changes in a direction in which a density of oxygen vacancies of the oxide semiconductor material increases.