Resistive memory device and fabrication method thereof
A resistive memory device and a fabrication method thereof are provided. The resistive memory device includes a bottom structure including a heating electrode, data storage materials, each of the data storage materials formed on the bottom structure in a confined structure perpendicular to the bottom structure, and having a lower diameter smaller than an upper diameter, an upper electrode formed on each of the data storage materials, and an insulation unit formed between adjacent data storage materials.
1. A method of fabricating a resistive memory device, the method comprising:
forming a first material layer having a first oxidation rate on a semiconductor substrate, on which a bottom structure is formed;
forming a second material layer, having a second oxidation rate lower than the first oxidation rate, over the first material layer;
patterning the second material layer and the first material layer to form pattern structures;
oxidizing surfaces of the pattern structures to form oxide layers;
forming an insulating layer on the semiconductor substrate, including the pattern structures having the oxidized surfaces;
planarizing the insulating layer to expose an upper surface of the second material layer;
forming storage node holes by removing the second material layer and the first material layer from the oxide layers; and
forming a data storage material in the storage node holes,
wherein an oxide layer on a surface of the first material layer is thicker than an oxide layer formed on a surface of the second material layer.
2. The method of claim 1 , wherein the forming the insulating layer comprises:
forming an air gap in the insulating layer, between the pattern structures.
3. The method of claim 1 , wherein the first material layer comprises silicon germanium, and the second material layer comprises polysilicon.
4. The method of claim 1 , wherein the data storage material comprises a phase-change material, a perovskite, or a transition metal oxide.
5. The method of claim 1 , further comprising:
forming, in the storage node holes, an electrode on the data storage material.
6. The method of claim 1 , wherein the oxidizing surfaces of the pattern structures comprises:
oxidizing the surface of the first material layer at a faster rate than the surface of the second material layer.
7. The method of claim 3 , further comprising:
controlling a thickness of the oxide layer on a surface of the first material layer by varying a concentration of germanium in the first material layer.