Thermoelectric Characteristics of Si/silicide Heterostructure Layers Fabricated by RF Magnetron Sputtering and RTA Techniques

Abstract

Various energy harvesting systems have attracted much attention due to the scarcity of the available energy resource. Especially, thermoelectric harvesting systems have been much studied because of their high adaptability or compatibility with the currently existing technologies in semiconductor, vehicle, and aerospace areas, etc. However, most of the studies have been focused on using Bismuth, Lead, and Telluride, known to be rare and toxic. These issues need to be overcome to make them more biocompatible and environment-friendly. Also, silicon(Si) was not recommended for the application of thermoelectric devices since it has intrinsically a low figure of merit (ZT) caused by its high thermal conductivity and low Seebeck coefficient. This issue also needs to be resolved. In this paper, we present a study on various Si/silicide heterostructure layers because these Si/silicide materials are usually non-toxic, abundant, and efficiently operated at relatively low temperatures. In addition, Schottky barriers are formed at individual interfaces of the heterostructure multilayers to control the relatively low-energy electrons and phonon-phonon scattering in favour of enhancing the ZT value. To fabricate the heterostructure layers, we used an RF magnetron sputtering technique and a rapid thermal annealing (RTA) process. The fabricated heterostructure layers were analysed by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Seebeck coefficient analyser,etc. Acknowledgment: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No. 2016R1D1A1B01007074). page