Lateral electrical transport and field-effect characteristics of sputtered p-type chalcogenide thin films

Investigating lateral electrical transport in p-type thin film chalcogenides is important to evaluate their potential for field-effect transistors (FETs) and phase-change memory applications. For instance, FETs with sputtered materials at low temperature (<= 250 C) could play a role flexible electronics or back-end-of-line (BEOL) silicon-compatible processes. Here, we explore chalcogenide films (Sb2Te3, Ge2Sb2Te5, Ge4Sb6Te7) multilayers, Hall measurements (in <= 50 nm films) 5 ultrathin films). The highest mobilities are measured Sb2Te3/GeTe superlattices (~18 cm2/V/s room temperature), over 2-3x higher than the other films. In achieve mobility up ~5.5 current on/off ratio ~10000, Ge2Sb2Te5 date. We also process optimizations (e.g., AlOx capping layer, type of developer lithography) uncover trade-offs towards realization acceptable ratio. Our study provides essential insights into optimization electronic devices based on chalcogenides.