An ICP (Inductively Coupled Plasma) etching system is designed and set up. The etching of Cu films is achieved at 70℃ in an $N_2$ and $Cl_2$ mixture plasma with ultra-violet radiation. The etch rate is 500 A/min at 70℃ and 1333 A/min at 220℃, respectively. Selective heating of CuClx and nonthermal effect by UV radiation are considered to make the lower temperature etching of Cu possible. All experiments have been done without RF-bias to the substrate. With RF-bias to the substrate, the etch characteristics can be improved.
