Internal stress control of transition-metal thin films

The characteristics of sputtered thin films are affected by ion bombardment during sputter deposition. An ion bombardment parameter Pi, which is based on the magnitude of the ion momentum and the impingement ratio of ions to metal particles, has been previously proposed as a means of expressing the effects of ion bombardment. In this study, the effects of ion bombardment parameter P-i on the internal stress of thin films were evaluated. Consequently, the internal stress of Ni and Cu thin films were observed to increase linearly with the increase of P-i; however, a Mo thin film exhibited the converse result. The results presented herein indicate that the characteristics of thin films, irrespective of the target, can be controlled via manipulation of parameter P-i.