Ruthenium thin films were deposited by plasma-enhanced atomic layer deposition (PEALD) technology using Ru(EtCp)₂ and oxygen plasma on the modified surface of silicon and SiO₂/Si substrates. The crystal structure, chemical composition, and morphology of films were characterized by grazing incidence XRD (GXRD), secondary ion mass spectrometry (SIMS), and atomic force microscopy (AFM) techniques, respectively. It was found that the mechanism of film growth depends crucially on the substrate temperature. The GXRD and SIMS analysis show that at substrate temperature T = 375 °C, an abrupt change in surface reaction mechanisms occurs, leading to the changing in film composition from RuO₂ at low temperatures to pure Ru film at higher temperatures. It was confirmed by electrical resistivity measurements for Ru-based films. Mechanical stress in the films was also analyzed, and it was suggested that this factor increases the surface roughness of growing Ru films. The lowest surface roughness ~1.5 nm was achieved with a film thickness of 29 nm using SiO₂/Si-substrate for deposition at 375 °C. The measured resistivity of Ru film is 18–19 µOhm·cm (as deposited).

Application of micro-Raman spectroscopy for the monitoring of quality of high-k (h-k) dielectric protective layer deposition onto the surface of a nanowire (NW) chip has been demonstrated. A NW chip based on silicon-on-insulator (SOI) structures, protected with a layer of high-k dielectric ((h-k)-SOI-NW chip), has been employed for highly sensitive detection of microRNA (miRNA) associated with oncological diseases. The protective dielectric included a 2-nm-thick Al₂O₃ surface layer and a 8-nm-thick HfO₂ layer, deposited onto a silicon SOI-NW chip. Such a chip had increased time stability upon operation in solution, as compared with an unprotected SOI-NW chip with native oxide. The (h-k)-SOI-NW biosensor has been employed for the detection of DNA oligonucleotide (oDNA), which is a synthetic analogue of miRNA-21 associated with oncological diseases. To provide biospecificity of the detection, the surface of (h-k)-SOI-NW chip was modified with oligonucleotide probe molecules (oDVA probes) complementary to the sequence of the target biomolecule. Concentration sensitivity of the (h-k)-SOI-NW biosensor at the level of DL~10⁻¹⁶ M has been demonstrated.