Selective low-temperature chemical vapor deposition of co

摘要

Abstract: Chemical vapor deposition of copper, in hot- and warm-wall reactors from a variety of copper (I) compounds of general formula XCuL$-n$/ where X $EQ $beta@-diketonate and $beta@- ketoiminate and L $EQ phosphine, olefin and alkyne, has been investigated. All compounds deposit high-purity copper, as determined by Auger electron spectroscopy, over the temperature range 100 - 400$DGR@C and pressure range 10 - 150 mtorr, with resistivities in the range 1.8 - 5.1 $mu@ohmcm. Selective deposition has been studied as a function of the neutral Lewis base ligand, L. The $beta@-diketonate)Cu(phosphine) compounds have been shown to deposit copper selectively onto Pt, W, and Cu in the presence of SiO$-2$/. The temperature range over which selectivity was observed was a function of the substituents on the $beta@-diketonate ligand. The ($beta@-diketonate)Cu(1,5- cyclo-octadiene) and ($beta@-diketonate)Cu(alkyne) compounds studied to date did not exhibit selectivity for the above metal substrates over SiO$-2$/. Deposition rates of up to 9,000 angstroms/min at 200$DGR@C have been obtained in a cold-wall CVD reactor under surface reaction limited conditions. Activation energy parameters measured from the temperature variation of the deposition rate were in the range 21 - 26 kcal/mol for (hfac)Cu(PMe$-3$/), (hfac)Cu(1,5-cyclo-octadiene) and (hfac)Cu(2- butyne). All three classes of compounds undergo a thermally induced disproportionation according to the general reaction 2XCu$+I$/L$-n$/ $YLD Cu$+o$/ $PLU Cu$+II$/X$-2$/ $PLU 2nL. This reaction pathway probably accounts for the high purity of the copper films. !30