Cu CVD from Copper(II) Hexafluoroacetylacetonate: I . A Cold Wall Reactor Design, Blanket Growth Rate, and Natural Selectivity

An atmospheric pressure cold wall reactor was designed and built for the purpose of studying the thermal decomposition of Cu(hfa) 2 as a repair technique for broken copper interconnection lines, using thermally biased substrates, and a laser to heat localized areas to a temperature appropriate for the deposition of pure copper. In this paper, a discussion of the design is presented, and theoretical and experimental blanket copper deposition growth rates in argon and forming gas are discussed. The primary goals of the present work were the design of the system, the determination of blanket growth rate characteristics, and examination of the tendency for natural selectivity to occur on two contiguous dielectric materials, SiO 2 and polyimide. In studies of natural selectivity, deposition was observed on SiO 2 , but not on contiguous polyimide at substrate temperatures of 340°C down to 270°C or lower, using argon as a carrier/diluent, and from 270°C down to 150°C, using argon/hydrogen mixtures (9 :1) as a carrier/diluent.