Deposition of CeOx/SnOx-based thin films via RF magnetron sputtering for resistive gas sensing applications

Cerium oxide-tin oxide (CeO x /SnO x ) thin films with varying Sn content were deposited using RF magnetron sputtering and investigated for hydrogen sensing applications. Structural, compositional, and morphological properties were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Gas sensing measurements showed effective hydrogen detection at room temperature, with the sensitivity strongly influenced by Sn content and oxygen vacancy concentration. Higher Sn concentration enhanced the sensing response, which was correlated with microstructural features obtained from AFM and EDX, as well as with the presence of Ce 3+ and Ce 4+ oxidation states identified by XPS. This study highlights the potential of CeO x /SnO x thin films for possible back-end-of-line integration and provides proof-of-principle for room-temperature hydrogen sensing. • CeO x /SnO x thin films deposited by RF magnetron sputtering at room temperature • Sn content and Ce 3+ concentration govern hydrogen sensing performance • Oxygen vacancies directly influence conductivity and gas response behavior • Hydrogen sensing achieved at room temperature in Sn-rich CeO x /SnO x films • Mixed-oxide thin films show strong potential for CMOS-compatible gas sensors.