The properties of Ru films deposited by remote plasma atomic layer deposition on Ar plasma‐treated SiO2

Abstract

AbstractBy using remote plasma atomic layer deposition (ALD), ruthenium thin films were deposited on SiO2 using bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a Ru precursor and an ammonia plasma as a reactant. Different plasma treatments were applied, and the best results were obtained with the Ar plasma‐treated SiO2 surface. The initial transition region usually observed with Ru deposition before continuous film formation was present, and the number of ALD cycles required to obtain a continuous film was reduced to about 35 cycles on the Ar plasma‐treated SiO2 substrates. The transition region of Ru cluster growth on Ar plasma‐treated SiO2 was investigated with transmission electron microscopy (TEM). Most of the Ru clusters were larger and better crystallized on the Ar plasma‐treated SiO2 than on untreated SiO2. Also, Ru films deposited on the treated SiO2 exhibited a (002) preferred orientated structure with a film resistivity of about 10.26 µΩ‐cm. The growth rates of Ru after passing the transition region were similar on both the treated and untreated SiO2 at about 1.7 Å/cycles. From the Auger electron spectroscopy (AES) spectrum, a very low content of oxygen was observed in the Ru films. About 9% carbon was detected by a rutherford backscattering spectrometer (RBS).