Organometallic Chemical Vapor Deposition of Copper from a New Organometallic Precursor

Abstract

ABSTRACTThin copper films have been grown on a variety of substrates using Cu(nona-F)2, (bis[4-(2,2,2-trifluoroethyl)imino-1,1,1,5,5,5-hexafluoro-2-pentanonato] copper(II)), a new volatile organometallic copper precursor, and the results are compared with those obtained using copper(II) betadiketonates. Copper films were grown in a cold wall reactor at reduced pressure at temperatures between 270°C and 350°C. For Cu(nona-F)2, films which are pure as determined by Auger electron spectroscopy and have a resistivity of 2.1 micro-ohm cm were deposited at temperatures above 270°C, 40°C lower than was possible using Cu(hfac)2. At low deposition temperatures, Cu(nona-F)2 shows some selectivity towards silicon oxide surfaces in preference to metals. The effects of CVD process parameters on the deposition rate and microstructure of the films were studied with a designed experiment and were statistically modeled. Deposition rates up to 70 nm/min were measured. The standard enthalpy of vaporization of Cu(nona-F)2 was found to be 9.6 kcal/mol.