CHEMICAL-VAPOR DEPOSITION OF COPPER FROM HEXAFLUOROACETYLACETONATO COPPER(I) VINYLTRIMETHYLSILANE - DEPOSITION RATES, MECHANISM, SELECTIVITY, MORPHOLOGY, AND RESISTIVITY AS A FUNCTION OF TEMPERATURE AND PRESSURE

Chemical vapor deposition (CVD) of copper from (hfac)copper(I)VTMS, wh ere hfac = hexafluoroacetylacetonato and VTMS = vinyltrimethylsilane h as been studied as a function of temperature and pressure. Analogous t o other (hfac)Cu(I)L compounds [L = trimethyl phosphine (PMe3), 1,5-cy clo-octadiene (COD) and 2-butynel, (hfac)CuVTMS also deposits pure cop per films via a quantitative thermally induced disproportionation reac tion. The reaction kinetics of (hfac)CuVTMS were examined in a warm-wa ll differential reactor over the temperature range of 130 to 200-degre es-C and pressure range of 10 to 500 mTorr. Deposition rates of up to approximately 5000 angstrom/min at 190-degrees-C and 500 mTorr were ob tained. Apparent activation energies of 43(5) and 10(2) kcal/mol at 10 and 500 mTorr precursor pressure, respectively were obtained. The dep osition rate was nearly first order over precursor partial pressure of 10 to 30 mTorr and zero order over 50 to 500 mTorr at 160-degrees-C. The data are consistent with a mechanism of chemisorption of (hfac)CuV TMS, dissociation to form (hfac)Cu and VTMS, disproportionation of (hf ac)Cu to form Cu metal and Cu(hfac)2, and desorption of Cu(hfac)2 and VTMS. A strong dependence of film resistivity on precursor partial pre ssure was observed. Selectivity for tungsten (W) surfaces in the prese nce of PECVD SiO2 was not observed under the conditions employed.