A NOVEL CU(II) CHEMICAL-VAPOR-DEPOSITION PRECURSOR - SYNTHESIS, CHARACTERIZATION, AND CHEMICAL-VAPOR-DEPOSITION

A nonfluorinated beta-diketonate precursor, bis(t-butylacetoacetato)Cu (II) or Cu(tbaoac)(2), was synthesized by modifying bis(dipivaloylmeth anato)Cu(II) or Cu(dpm)(2) for chemical vapor deposition (CVD) of copp er. The complex was characterized by a variety of techniques, such as melting point determination, mass spectrometry, infrared spectroscopy, elemental analysis, thermogravimetric and differential thermal analys is, and x-ray diffraction. Cu(tbaoac)(2) has a higher sublimation rate than Cu(dpm)(2) over the temperature range 90-150 degrees C. Pyrolysi s of Cu(tbaoac)(2) leads to the formation of copper films at 225 degre es C, compared to 330 degrees C for Cu(dpm)(2). As-deposited copper fi lms were highly dense, mirror-bright, adhered strongly to SiO2, and sh owed a resistivity of less than 2.9 mu Ohm-cm at a thickness as low as 1300 Angstrom. A possible mechanism for the decomposition of the liga nd tbaoac has been proposed.