Chemical vapour deposition of amorphous Ru(P) thin films from Ru trialkylphosphite hydride complexes

Abstract

The ruthenium phosphite hydride complexes H₂Ru(P(OR)₃)₄ (R = Me (1), Et (2), ⁱPr (3)) were used as CVD precursors for the deposition of films of amorphous ruthenium–phosphorus alloys. The as-deposited films were X-ray amorphous and XPS analysis revealed that they were predominantly comprised of Ru and P in zero oxidation states. XPS analysis also showed the presence of small amounts of oxidized ruthenium and phosphorus. The composition of the films was found to depend on ligand chemistry as well as the deposition conditions. The use of H₂ as the carrier gas had the effect of increasing the relative concentrations of P and O for all films. Annealing films to 700 °C under vacuum produced films of polycrystalline hcp Ru while a flowing stream of H₂ resulted in polycrystalline hcp RuP.