Forced convection magnetoelectroplating for enhanced semiconductor metallization

An efficient method that controls the rate and characteristics of copper electroplating for semiconductor metallization is demonstrated. Unlike typical electroplating processes, the proposed method operates with a forced flow of the electrolyte in the presence of an externally applied magnetic field, hence inducing a Lorentzian force that enhances the transport of depositing ions toward deposition regions. The magnitude of the induced force has been estimated to be at least one order of magnitude larger than other forces encountered in electroplating processes. A constructed experimental setup is described and used to demonstrate and investigate effects of induced Lorentzian forces on the rate and formation characteristics of deposited copper metallization. The obtained experimental results clearly demonstrate the technical and economical impact of the method in terms of providing a compact (low porosity) deposit with thin sidewalls and reducing the required deposition time by controlling the intensity of the applied magnetic field and the electrolyte flow velocity. The method holds promise for related metallization issues.