300 mm CMOS-compatible fabrication of Ru2Si3 sub-50 nm thin films and characterization

Abstract

We report the thermoelectric characterization of Ru2Si3 thin films. Ruthenium (VI)-silicide was formed via silicidation by rapid thermal processing of ruthenium on amorphous, undoped silicon of different thicknesses (sub-50 nm). 300 mm wafer level processes were applied, utilizing physical and chemical vapor deposition methods. High-temperature-XRD, energy dispersive x-ray spectroscopy, transmission electron microscopy, and time-of-flight secondary ion mass spectrometry confirm the formation of single-phase Ru2Si3 thin films. Thermoelectric measurements reveal exceptionally high Seebeck coefficients of up to 1.5 mV/K close to room temperature in dependence of adjustable oxide nanoskins. Due to the thermal stability of the nanoskins, fine-tuning of the thermoelectric properties by rapid thermal processing could be applied in a large temperature range.