Effect of the cyclic delivery of (hexafluoroacetylacetonate)Cu~((I)) X(3,3-dimethyl-1-butene) pulse and Ar purge gas on the low temperature copper metalorganic chemical vapor deposition

摘要

Cu thin films were deposited on the sputter-deposited Ta/Si substrate using cycles of alternate supply of (hexafluoroacetylacetonate)Cu~((I)) (3, 3-dimethyl-l-butene) pulse and argon purge gas. The growth temperature was as low as 70℃ and 200-1000 cycles were performed to deposit films in pulsed-metalorganic chemical vapor deposition (MOCVD) with a growth rate of ～0.75 A/cycle. Cross-sectional scanning electron microscopy of the pulsed-MOCVD Cu films showed continuous and uniform films, while the MOCVD Cu films showed void formations. Also, x-ray diffraction patterns of the Cu films showed the preferential crystallographic orientation of the (111) plane. The Cu films grown by MOCVD and pulsed MOCVD, both contained oxygen (O), carbon (C), and fluorine (F) as impurities. The impurities of C and F atoms were hard to detect in the bulk films and only the O atom was detected in both films. The O concentration in pulsed-MOCVD films was much lower than that in MOCVD films with a concentration ratio below 1/3.