The effects of processing parameters in the chemical vapor deposition of cobalt from cobalt tricarbonyl nitrosyl

This paper reports the development of a thermal chemical vapor deposition p rocess for pure cobalt from the source precursor cobalt tricarbonyl nitrosy l for incorporation in integrated circuit silicide applications. Studies we re carried out to examine the underlying mechanisms that control Co nucleat ion and growth kinetics, including the effects of key process parameters on film purity, texture, morphology, and electrical properties. For this purp ose, systematic variations were implemented for substrate temperature, prec ursor flow, hydrogen reactant flow, and deposition time (thickness). Result ing films were analyzed by Rutherford backscattering spectrometry, X-ray ph otoelectron spectroscopy, X-ray diffraction, four-point resistivity probe, scanning electron microscopy, and atomic force microscopy. These investigat ions identified an optimized process window for the growth of pure Co with resistivity of 9 +/- 2 mu Omega cm, smooth surface morphology, and root-mea n-square surface roughness at or below 10% of film thickness. (C) 1999 The Electrochemical Society. S0013-4651(98)08-015-X. All rights reserved.