Incubation time for chemical vapor deposition of copper from hexafluoroacetylacetonate–copper(I)–vinyltrimethoxysilane

2019/6/17

The incubation time in a metal-organic chemical vapor deposition (MOCVD) system using copper (I)–hexafluoroacetylacetonate Vinyltrimethoxysilane (Cu(hfac)(VTMOS)) as the precursor to grow copper films has been investigated. For film deposition on a TiN/Si substrate in the presence of H2 at 473 K, the incubation time is 88 min, while it decreases to 4.3 min on a Pt-seeded surface. The incubation phenomenon is attributed to a heterogeneous nucleation process involving surface reactions of precursor. By using a first-order reaction approximation, the incubation time is correlated with the nucleation rate constant to give an activation of 5.5 kcal/mol in a temperature range of 463 to 498 K, indicative of a surface-reaction controlled regime concerning heterogeneous Cu nucleation. Observation of the very early stage of film growth by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) reveals that growth of nucleus prevails in the period of incubation time.