RF-Ionised Physical Vapour Deposition for Cu Thin Films: Deposition on Polymer Substrate

Ionised physical vapour deposition (IPVD), performed with a magnetron and a one-loop radio frequency (RF) coil, was used to deposit copper thin films on polymer substrates in order to cover complex shapes. This process allows improving the films conformity and their resistivity by ionising the sputtered vapour. The coil coupling was adapted in order to optimise the process. The film resistivity is influenced by the RF power and the pressure. A substrate cleaning phase, required to obtain good film adhesion, was done using the RF coil. The influence of treatment parameters (pressure, RF power, duration) was studied on the adhesion. Optical emission and absorption spectroscopy were performed to identify and quantify neutral and ionic copper species in the plasma and furthermore to study the influence of the coil on the vapour properties.