A New Liquid Precursor with Improved Thermal Stability for Chemical Vapor Deposition of Copper

Abstract

A new liquid precursor (hfac)Cu(teovs) (I), where hfac = hexafluoroacetylacetonate and teovs = triethoxyvinylsilane, was developed for chemical vapor deposition (CVD) of copper thin films. This copper(+1) precursor is more thermally stable than the previously known (hfac)Cu(tmvs), where tmvs = trimethylvinylsilane. Using a fully automated CVD reactor equipped with a direct liquid injection and vaporizer system, pure copper films were deposited on TiN‐covered 6 in. diam silicon wafers with a high deposition rate. Excellent uniformity of the deposited films was obtained in some cases. An analogous solid compound (hfac)Cu(dmomvs) (II), dmomvs = dimethoxymethylvinylsilane was also synthesized and structurally characterized. ¹H‐NMR analysis revealed that compound II is thermally less stable than compound I. For the Cu(+l) precursors of the type (hfac)Cu(vinylsilane), the thermal stability of the complex apparently reflects the electron donating capability of the substituents attached to the silicon atoms.