THERMAL CHEMICAL-VAPOR-DEPOSITION OF COPPER FROM HEXAFLUOROACETYLACETONATE CU(I) VINYLTRIMETHYLSILANE - KINETIC-STUDIES

The role of hydrogen in the chemical vapor deposition of copper from h exafluoroacetylacetonate Cu(I) vinyltrimethylsilane was investigated b y depositing copper using pure hydrogen, pure helium or mixtures of th ese gases at substrate temperatures between 130 and 180 degrees C, pre cursor partial pressures between 1.0 and 6.0 mTorr at 250 mTorr total pressure in a vertical how stagnation point cold-wall reactor. The act ivation energy for copper growth from (hfac)Cu(vtms) using either hydr ogen or helium was comparable (4000-6000 cal/mol). The him composition was independent of the type of diluent or carrier gas and the film re sistivity of the data used was routinely near 2.2 mu Omega cm for thic k films (> 5000 Angstrom). Film growth rates between 60 and 360 Angstr om/min were obtained with no significant correlation with the type of carrier/diluent gas used. Approximate first-order dependence of copper growth rate on precursor concentration was observed. The observed zer o-order dependence of growth rate on hydrogen concentration suggests a chemically inactive role for hydrogen in copper deposition. Fundament al surface reaction mechanisms consistent with our experimental observ ations are proposed. (C) 1998 Elsevier Science B.V. All rights reserve d.