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, SiO2 and polyimide. In studies of natural selectivity, deposition was observed on SiQ, but not on contiguous polyimide at substrate temperatures of 340~ down to 270~ or lower, using argon as a carrier/diluent, and from 270~ down to 15O~ using argon/hydrogen mixtures (9:1) as a carrier/diluent.

The laser-assisted chemical vapor deposition of copper onto thermal SiO~-overcoated Si wafers in a cold wall atmospheric pressure reactor, using Cu(hfa)2 in Ar/H 2 (10%), or argon as carrier/diluent is discussed. The substrate was biased thermally at 130~ in Ar/H2 or 200~ in Ar. A multiline (k = 488 to 514 nm) continuous wave 4 ~m focused spot diameter, 150 mW argon ion laser was used to heat the spot to a temperature at, or above, the required decomposition temperature, ->150~ in Ar/H2 and ->250~ in Ar. The steady-state temperature on the SiO2 prior to the beginning of deposition was estimated using a modified Lax model, since there is no convenient way of measuring it experimentally. Under the conditions employed, a maximum copper spot growth rate of 0.12 ~m/min was obtained at 0.095 W laser power. The laser-assisted growth rates in the present system can be predicted within a factor of two from the kinetic model of Ehrlich and Tsao. An incubation time which varies inversely with power, and with the composition of the carrier gas was observed on SIO2, due to the low absorption of the incident energy in the SiO2 at the small laser power used. Auger electron spectroscopy, of the copper deposits has shown small levels of carbon and oxygen. It is possible that the temperature at the center of the beam spot is greater than 400~ after copper begins to nucleate, and that the organic ligands undergo some fragmentation, or that some degree of oxidation and carbonaceous contamination occurs upon exposure to air when specimens are removed from the reactor. Using the described deposition methods, it should be possible to effect repair of broken copper lines on a microelectronic package in a minute or two.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 137.207.120.173 Downloaded on 2014-11-18 to IP