Plasma Enhanced Atomic Layer Deposition of Ruthenium Films Using Ru(EtCp)2 Precursor

Abstract

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).

Hydrogen Plasma-Assisted Atomic Layer Deposition of Ru with Low Oxygen Content

“…Moreover, Ru shows a low sheet resistance (7.1 µΩ•cm for bulk), high work function (4.7 eV), and low solid solubility in Cu [1]. Moreover, Ru exhibits superior catalytic activity, for example, in the oxygen/hydrogen evolution reaction (OER/HER) and hydrocarbon/natural gas reforming, and is less expensive than other noble metals (Pt, Pd, and Ir) [2][3][4][5]. Therefore, Ru is extensively utilized and studied in various elds such as semiconductors (e.g., electrodes for metal-oxide-semiconductor eld-effect transistors (MOSFETs) and dynamic randomaccess memory (DRAM) capacitors) [6][7][8][9], electrochemical devices (e.g., electrolysis and hydrocarbonfueled solid oxide fuel cells (SOFC)) [10,11], and catalysts (e.g., carbon capture devices) [12,13].…”

2-Phenylimidazole Corrosion Inhibitor on Copper: An XPS and ToF-SIMS Surface Analytical Study

“…The manner in which corrosion inhibitors bond to the surface is critical in determining whether they can effectively mitigate corrosion. The latter can be investigated using surface analytical techniques, in particular X-ray photoelectron spectroscopy (XPS) and time-offlight secondary ion mass spectrometry (ToF-SIMS) [22][23][24][25][26][27][28]. The recent development of gas cluster ion beam (GCIB) technology in combination with surface analytical techniques enables a detailed study of very thin surface layers [29][30][31][32][33][34][35], e.g., the very thin surface layers of corrosion inhibitors.…”