Bottom-up filling of submicrometer features in catalyst-enhanced chemical vapor deposition of copper

A formation process for copper bottom-up filling of submicrometer via holes and trenches using iodine as a catalytic surfactant and hexafluoroacetylacetonate-copper-vinyltrimethylsilane in catalyst-enhanced chemical vapor deposition of copper is presented. The film growth rate of copper at the bottom of the submicrometer features is continuously accelerated until the features are filled, and this results in the bottom-up filling of submicrometer features previously considered not viable in vacuum deposition techniques. The accelerated film growth appears to be due to the accumulation of the catalytic surfactant iodine on the surface of the copper films growing at the bottom of the submicrometer features believed to result from reduction of the sidewall area in the submicrometer features as the film grows. The newly developed technique for the copper bottom-up filling of submicrometer features will have a great impact on on-chip copper interconnects for the next generation of microelectronic devices. Moreover, this bottom-up growth mode in submicrometer features is expected to be universal to other systems of chemical vapor deposition in which a catalytic surfactant is used.