Effects of Ar plasma treatment for deposition of ruthenium film by remote plasma atomic layer deposition

Abstract

Ruthenium thin films were deposited on argon plasma-treated SiO 2 and untreated SiO 2 substrates by remote plasma atomic layer deposition using bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp) 2 ] as a Ru precursor and ammonia plasma as a reactant. The results of in situ Auger electron spectroscopy (AES) analysis indicate that the initial transient region of Ru deposition was decreased by Ar plasma treatment at 400 C, but did not change significantly at 300 C. The deposition rate exhibited linearity after continuous film formation and the deposition rates were about 1.7 Å /cycle and 0.4 Å /cycle at 400 C and 300 C, respectively. Changes of surface energy and polar and dispersive components were measured by the sessile drop test. The quantity of surface amine groups was measured from the surface nitrogen concentration with AES. Furthermore, the Ar plasma-treated SiO 2 contained more amine groups and less hydroxyl groups on the surface than on untreated SiO 2 . Auger spectra exhibited chemical shifts by Ru-O bonding, and larger shifts were observed on untreated substrates due to the strong adhesion of Ru films.