Techniques are disclosed for an electron cyclotron rotation (ECR)-enhanced hollow cathode plasma source (HCPS). A cylindrical magnet is placed around the neck of a hollow cathode under the influence of an RF field. A plasma gas is introduced in the hollow cathode that undergoes phase transition to a plasma containing free electrons and gas ions. The magnetic field of the magnet causes ECR that confines free electrons to a narrow spiraling beam traveling down the body of the hollow cathode. Unlike traditional methods, the present ECR-enhanced design confines the electrons and ions to a narrow path away from the walls of the cathode. The high-density, stable plasma is available at the distal end of the hollow cathode. A multicavity design utilizes multiple cavities with multiple aligned magnets in a single reactor suitable for various processes including, PECVD, PEALD, ALE, etc.