Ruthenium(II) MOCVD Precursors for Phosphorus-Doped Ruthenium Layer Formation

The synthesis and solid-state structure of Ru(CO)2(PEt3)2(O2CR)2 (4a -f , R = Me, Et, i Pr, t Bu, CH2OMe, CF3) is reported. The vapor pressure of 4a -f was measured, ranging from 6.3 mbar (4f ) to 14.8 at 190 °C (4e ). Complexes 4a -f decompose between 210-350 °C of which 4c shows the lowest (248 °C) and 4e (280 °C) the highest onset temperature. TG-MS studies (4f ) showed subsequent decarbonylation and decarboxylation processes. To determine the gas phase composition VT IR studies were performed. Based on TG-MS, VT IR and DFT calculations decomposition mechanisms are discussed. Complexes 4a -f are suited as MOCVD precursors, producing dense layers of 25-50 nm thickness, consisting of 57 at-% Ru, up to 18.2 at-% P and as impurities C, N and O. A carbon-free Ru(P) layer was obtained with 4a as CVD precursor.