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

Abstract

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.

Kinetics of Copper CVD Using Solution Delivery of Cu(hfac)[sub 2] and Isopropanol

“…4. This is 50 times faster than the rate for H 2 reduction of Cu͑hfac͒ 2 reported by Chen et al 15 using a partial pressure of Cu͑hfac͒ 2 that was 10 times lower than the present…”

“…7,12 A comparison with previous H 2 reduction results using very low precursor partial pressure also shows that the kinetics must become positive order in alcohol at very low alcohol pressure. 15 Single-surface intermediate model.-This complex reaction order behavior is strongly suggestive of a series reaction mechanism. In the simplest case, the precursor is assumed to react at a clean surface to produce an adsorbed intermediate.…”

Deposition of Copper by the H2-Assisted Reduction of Cu(tmod)2 in Supercritical Carbon Dioxide: Kinetics and Reaction Mechanism

“…The apparent activation energy of the overall reaction was found to be 51.9 kJ/mol. By comparison, the activation energy for metal organic chemical vapor deposition (MOCVD) using copper(II) hexafluoroacetylacetone, Cu(hfac) 2 , has been reported to be ∼75−80 kJ/mol. , In those studies, the surface reaction was assumed to be the rate-limiting step. The activation energy calculated from data reported for MOCVD using bis(2,2,6,6-tetramethyl-3,5-heptadionato)copper(II), Cu(tmhd) 2 , was ∼60 kJ/mol .…”

Low-Temperature Deposition of Conformal Copper Films in Supercritical CO2by Catalytic Hydrogen Reduction of Copper Hexafluoroacetylacetonate

“…A current method widely used for copper deposition is electroplating, which requires a copper seed layer (work as a cathode) formed with physical vapor deposition. Also, various kinds of chemical vapor deposition (CVD) techniques have been studied for conformal copper deposition over the past decade in order to replace the electroplating with the CVD, which is favorably used in the semiconductor industry. − Although the recent CVD techniques enable us to make a conformal copper film at a rapid growth rate and fill small features with no voids and seams, − adhesions of copper films on barrier layers such as TiN, TaN, and Ta are poor in most of the techniques . High deposition temperature (>200 °C) is another drawback of this technique.…”