High-rate reduction of copper oxide using atmospheric-pressure inductively coupled plasma microjets

Reduction of copper oxide was performed using an atmospheric-pressure inductively coupled plasma (AP-ICP) microjet while varying the input power P between 15 and 50 W. Cuprous oxide (Cu2O) and cupric oxide (CuO) were formed on the sputtered Cu surface by thermal annealing. Dynamic behavior of the microplasma jet, optical emission from H atoms, the substrate temperature, chemical bonding states of the treated surface, and the thickness of the reduced Cu layer were measured to study the fundamental reduction process. Surface composition and the thickness of the reduced Cu layer changed significantly with P. Rapid reduction of CuO and Cu2O was achieved at a rate of 493 nm/min at P = 50 W since high-density H atoms were produced by the AP-ICP microjet.