Presentation Information
[8p-A21-3]Study of thermoelectric properties in sputtered Si-Ge thin films
〇(P)Madhuvathani Saminathan1, Priyanka Sangwan1, Kenji Watanabe1, Mahasuru Matsunami1, Tsunehiro Takeuchi1 (1.Toyota Tech. Inst.)
Keywords:
Thermoelectrics,Thin films
Thermoelectric (TE) technology offers a sustainable, and scalable approach to microscale power generation in modern electronic architectures. The efficiency of a TE material is governed by: ZT= (S2/(rk))T, where S, r, k, and T represent the Seebeck coefficient, electrical resistivity, thermal conductivity, and absolute temperature, respectively. A primary challenge in TE material design involves decoupling the interdependent transport parameters to maximize the electrical power factor and ensure low k. While high-performance chalcogenide-based materials have traditionally dominated TE applications, their commercial deployment is hindered by high production costs, material toxicity, and poor long-term sustainability. Si-Ge thin films have emerged as highly promising, eco-friendly alternatives due to their seamless compatibility with standard CMOS manufacturing processing, and remarkable structural tunability at the nanoscale. A critical limitation of conventional bulk Si-Ge alloys are their poor TE performance near room temperature, a consequence of high k. In contrast, thin-film architectures offer a pathway to overcome these bulk limitations by exploiting nanoscale transport phenomena. In this work, we present a systematic investigation of the structural and TE transport properties of sputtered Si-Ge thin film, explicitly focusing on the transition from bulk-like behavior to nanostructured transport dynamics. The films were fabricated via RF sputtering under a multi-dimensional parameter space, featuring variations in growth conditions, post-deposition thermal history, and composition via doping. Variations in these microstructural features demonstrate sensitivity to the processing windows, underscoring the role of processing-structure-property dynamics in nanoscale transport to surpass bulk limitations, which will be discussed in the presentation.