Bisethylacetoacetato Cu(II) as a novel metal-organic precursor for Cu film production by plasma-enhanced chemical vapor deposition toward ultra-large-scale integration metallization

Abstract

Bisethylacetoacetato Cu(II), referred to as Cu(etac)2, was synthesized and used as a novel metal-organic precursor to produce Cu films by PECVD processing. Cu(etac)2 is a nonfluoride compound that is solid at room temperature with reasonable volatility at 120–150 °C of 0.8 Torr. Effects of selected process variables on the characteristics of Cu film deposition were studied. Considered variables were plasma power, hydrogen flow rate, deposition time, substrate temperature, and precursor temperature. The process conditions to give Cu films of a high quality were determined. The electrical resistivity approached 2 μΩ · cm as the Cu film thickness became greater than 2500 Å. The conformality of the Cu film deposition by PECVD was sufficient to result in complete via-hole fillings of wafers patterned for 256 Mb DRAM.