Novel fabrication method of metallic glass thin films using carousel-type sputtering system

Abstract

We propose a novel method of fabricating metallic glass thin films using a carousel type sputtering system. In conventional methods of fabricating metallic glass thin films using alloy targets, control of the alloy composition is difficult. However, since r.f. power for each target can be controlled independently in the proposed system, it is easy to control the alloy composition. Thin films of various alloy compositions are fabricated. In this work, near-equiatomic CuZr thin films are fabricated by the sputtering system with rotational speeds of the substrate holder ranging from 10 to 50 rpm. Small-angle XRD revealed that the specimen fabricated with rotation at 10 rpm had a multilayer structure. The specimen fabricated with rotation at 50 rpm exhibited a glass transition temperature of 672 K, a crystallization temperature of 715 K, and a supercooled liquid region of 43 K. However, although the XRD results indicated that the specimen fabricated with rotation at 30 rpm was in an amorphous state, it exhibited solid-state amorphization rather than glass transition before the crystallization in DSC measurement. Thus, the specimen did not become a metallic glass. Clearly, sputtering rate is a very important parameter in the fabrication of metallic glass thin films by the proposed sputtering system. These results have shown the proposed method to be effective in fabricating metallic glass thin films.