A study of the NF3 plasma etching reaction with cobalt oxide films grown on an inorganic compounds

Abstract

In this study, an NF3 plasma etching reaction with a cobalt oxide (Co3O4) films grown on the surface of inorganic compounds using granite was investigated. Experimental results showed that the etching rate can be up to 1.604 μm/min at 380 °C under 150 W of RF power. EDS and XPS analysis showed that main reaction product is CoF2, which is generated by fluorination in NF3 plasma. The etching rate of cobalt oxide films grown on inorganic compounds in this study was affected by surface roughness and etch selectivity. This study demonstrates that the plasma surface decontamination can effectively and efficiently remove contaminated nuclides such as cobalt attached to aggregate in concrete generated when decommissioning of nuclear power plants.

Keywords

• Decontamination
• Radioactive waste
• Cobalt oxide
• Plasma etching
• Cobalt fluoride