Effect of ionized species on thickness distribution of Al films on inner-wall of small hole deposited by HiPIMS

Abstract

HiPIMS deposition of metal nitride and oxide has been widely studied because it enables to deposit under low temperature. In order to clarify the transportation behavior of the sputtered species into the millimeter-scale tubular structure, this study focused on the effect of ion-to-neutral ratio in the HiPIMS plasma on the film thickness distribution on inner-wall surface. Control of ion-to-neutral ratio of aluminum was achieved by changing pulse peak current density under constant input power and pulse width. The role of ionized species and its effect on the particle trajectory into the tubular structure are discussed by comparing different thickness distributions.