Characterization of Tungsten Silicide Films Fabricated by RF Magnetron Sputtering and RTA Techniques

Abstract

Recently, various energy harvesting systems have attracted much attention as low-power and small-sized electronic systems have been increasingly demanded. Conventionally, thermoelectric harvesting systems have been mainly fabricated using Bismuth Telluride or Lead Telluride. Unfortunately, these materials are known to be toxic, rare, and operating usually at high temperatures, having limitations in their applications. To resolve the issues, the silicide-based thermoelectric harvesting systems have been investigated, due to the superior physical properties of silicide materials that are formed easily by the thermal reaction of silicon and metal atoms. Also, the silicide materials are generally non-toxic, abundant, and operating at low temperatures. In this study, we fabricated the tungsten silicide layer, as a thermoelectric material, using an RF magnetron sputtering technique as well as a rapid thermal annealing (RTA) process. To investigate the RTA effects on the silicide layer, we characterized the electrical conductivity, phase change and Seebeck coefficient by using the Van der Pauw method, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Seebeck coefficient analyser, etc.