Effect of incubation time on preparation of continuous and flat Ru films

Abstract

Ru films were deposited from Ru(C7H11)(C7H9)–O2 and Ru(C7H11)2–O2 systems on SiO2 (native oxide)/(001)Si, HfSiON/SiON/(001)Si, and HfO2/SiON/(001)Si substrates by pulsed metal organic chemical vapor deposition. Ru deposition was hardly observed at 210 °C at the early stage of the deposition, i.e., incubation time, and this time depended on the source systems and the kinds of the substrates as well as the deposition temperature. After this incubation time, the deposition amount almost linearly increased with the deposition time. This slope, i.e., the deposition rate after the incubation time, was hardly independent of the kinds of substrates. This slope changed by the source systems. The minimum deposition amount to get films with the apparent resistivity below 100 μΩ cm and its average surface roughness depended on the kinds of the substrates, the source systems and the deposition temperature. More importantly, the shorter incubation time of the film deposition resulted in the thinner continuous films with smaller surface roughness irrespective of the source systems. This clearly shows the effect of the incubation time on the preparation of continuous and thin flat Ru films.