Surface morphology of a Cu substrate flattened by a 2″ photoemission‐assisted ion beam source

Abstract

Photoemission‐assisted plasma irradiation of a 2″ Cu substrate was performed to clarify the effect of ion impingement on the substrate. With the use of a photoemission‐assisted plasma apparatus, the photoemission‐assisted plasma was evaluated by optical emission spectroscopy and discharge characteristics. The density ratio of Ar ions and atoms increases with increasing the bias voltage of photoemission‐assisted plasma. Changes in the surface morphology of the substrate were investigated using atomic force microscopy. Sufficient ion density can be obtained in photoemission‐assisted Townsend discharge, and surface roughness of the Cu substrate decreased as the plasma irradiation time increased. This result indicates that ion impingement from photoemission‐assisted Townsend plasma can sputter the metal surfaces, leading to a decrease in surface roughness. Copyright © 2011 John Wiley & Sons, Ltd.