Influence of film-growth conditions on c-axis orientation in sputtered Co-Cr thin films

Abstract

Double‐ and multiple‐layered Co‐Cr thin films have been prepared to clarify the dominant factors in the c‐axis orientation at the early stage of the film growth. The optimized process condition in the facing‐targets sputtering system is likely to promote the c‐axis self‐orientation in the films since they can grow on the plasma‐bombardment‐free substrate. This effect was confirmed by depositing the films on the poorly oriented Co‐Cr film as the underlayer. Meanwhile, when the well‐oriented Co‐Cr thin film was used as the underlayer, a continuous growth of crystallites resulted in the improvement of the c‐axis orientation in the growing film even under process conditions unfavorable for depositing the well‐oriented films. This Co‐Cr underlayer effect continues until the thickness of the depositing film reaches about 2000 Å, suppressing the influence of the unfavorable sputtering condition.