The effect of an iodine source on nucleation and film properties of Ru films deposited by chemical vapor deposition

摘要

The chemical vapor deposition of Ru films from (2,4-dimethylpentadienyl)(ethylcyclopentadienyl)Ru and O_2 was carried out both with and without CH_3I addition. X-ray photoelectron spectroscopy indicates that the addition of CH_3I does not significantly increase the amount of carbon in the films. Adsorbed iodine on the growing film surface results in denser, more uniform nucleation and smaller-grained, smoother films. The root-mean-square roughness of 60 nm films decreased from 8.42 to 5.62 nm for no CH_3I and CH_3I addition, respectively. Adsorbed iodine segregates through the films to the surface during growth, resulting in a continuously depressed deposition rate. The adsorbed iodine blocks oxygen dissociation sites, reducing the oxygen supply available to decompose the ligands of the Ru precursor.