Fluorinated aminoalkoxide Cu-II complexes: new CVD precursors for deposition of copper metal

摘要

[[abstract]]Volatile low-melting Cu-II metal complexes of formula Cu[OC(CF3)(RCH2NHR2)-C-1](2) (R-1 = CF3 or CH3; R-2 = CH2CH2OMe, Bu-i, or Bu-t) and Cu[OC(CF3)(RCH2NMe2)-C-1](2) (R-1 = CF3 or CH3) have been synthesized and characterized by spectroscopic methods. A single-crystal X-ray diffraction study on Cu[OC(CF3)(2)CH2NHCH2CH2OMe](2) shows that one methoxyethyl group of the aminoalkoxide ligand forms an intramolecular dative bond to the Cu atom to produce a square-pyramidal geometry at the metal center, while the second is linked to the Cu atom of the adjacent molecule, giving an N2O4 octahedral coordination arrangement. For the second Bu-i-substituted complex, Cu[OC(CF3)(2)CH2NHBui](2), the X-ray structural analysis demonstrated an N2O2 square-planar geometry, with one alkoxide oxygen atom forming strong H-bonding to an adjacent water molecule. Metal CVD experiments were carried out, showing that the source reagents Cu[OC(CF3)(2)CH2NHBui](2), Cu[OC(CF3)(2)CH2NHBut](2), and Cu[OCMe(CF3)CH2NHBui](2), which possess a secondary amino group, are capable of depositing copper metal at temperatures of 250-300 degreesC under inert Ar carrier gas, while Cu[OCMe(CF3)CH2NMe2](2), with a tertiary amine group, requires the use of reductive H-2 carrier gas to induce metal deposition at lower temperatures.