Oxygen penetration energy change according to surface roughness and transmission electron microscope surface analysis. Photo = Jeong Se-young, a professor at Pusan National University
A Korean research team has opened up the possibility of manufacturing non-oxidized copper by identifying the origin of copper oxidation at the atomic level for the first time in the world.
The Ministry of Science and ICT announced that a research team led by Pusan National University Professor Jeong Se-young, Sungkyunkwan University Professor Kim Young-min, and Mississippi State University Professor Seong-gon Kim have identified the principle of copper oxidation in theory and experiment using an ultra-flat copper thin film with monoatomic layer roughness.
The research team confirmed that oxidation did not occur by implementing a monoatomic layer-level ultra-flat copper thin film with a self-developed thin film growth device.
As a result of observing the ultra-flat copper thin film exposed to air for one year using a high-resolution transmission electron microscope, etc., neither the natural oxide film normally observed on the copper surface nor even the atomic level oxidation was observed.
In addition, as a result of calculating the energy change for oxygen to enter the inside of copper, when the surface roughness is two or more atomic layers, oxygen penetration into the inside of copper proceeds easily, whereas when it is a perfectly flat surface or a monoatomic layer, it is very large for oxygen penetration. He revealed that oxidation does not occur at room temperature because it requires energy. Oxygen present on the surface of the ultra-flat thin film also has a self-regulating function that suppresses oxidation by pushing out other oxygen from approaching when 50% of the sites where oxygen can exist are filled.
The research team believes that it will be an opportunity to economically replace gold used in nano circuits with copper thin films by accurately revealing the cause of copper oxidation used throughout the industry.
Professor Jeong Se-young said, “The replacement of gold with copper with high electrical conductivity will contribute to economic advantages and miniaturization of equipment.
Meanwhile, the research results, which were carried out with support from the Ministry of Science and ICT, such as individual basic research and group research support project, were published on the 17th in the international academic journal Nature.