Precursors for Copper Chemical Vapor Deposition

• Main Author: BuFaroosha, Muna
• Other Authors: Andrew Maverick
• Format: Others
• Language: en
• Published: LSU 2002
• Subjects: Chemistry
• Online Access: http://etd.lsu.edu/docs/available/etd-0606102-074339/

The main objective of this study was to synthesize precursors that are capable of producing copper films of high quality by chemical vapor deposition (CVD). We investigated some copper(I) and copper(II) complexes as precursors for chemical or photochemical vapor deposition. In chapter 2, we synthesized a series of Cu(hfac)₂(amine) adducts, where hfac^- is hexafluoroacetylacetonate and the amines are: dimethylamine, isopropylamine, allylamine, pyrrolidine, and piperidine. The efficiency of these adducts compared to Cu(hfac)₂(H₂O) as Cu-CVD precursors was examined under hydrogen. We found that among these amine adducts, Cu(hfac)₂(allylamine)₂ gave the best deposition rate under hydrogen. Their capability as self reducing precursors was tested under the inert gas nitrogen. All the amine adducts in this study deposited copper films under nitrogen, which demonstrated their ability as self reducing precursors. All the amine adducts except Cu(hfac)₂(allylamine)₂ exhibited square pyramidal geometry where the hfac^- ligand twists out of the plane permitting one of the Cu-O bonds to take the apical position. Chapter 3 summarizes the reactions of Cu(hfac)₂ and certain amines which resulted in compounds with formulas other than Cu(hfac)₂L. Here we learned that the reaction between Cu(hfac)₂ and NEt₂ does not afford the adduct Cu(hfac)₂(NEt₃) as reported in the literature. The species that we were able to isolate from this reaction indicate that this reaction is not a simple adduct formation but possibly proceeds via proton transfer. In general we concluded from the work presented in this chapter that bulky amines give different adducts than the desired Cu(hfac)₂(amine). The second class that we attempted to examine as copper precursors for chemical or photochemical vapor deposition was the Cu(I)-amide clusters. In chapter 4 we studied the photoactivities of a series of these tetramers: [CuN(SiMe₃)₂]₄, [CuN(t-Bu)(SiMe₃)]₄, [CuNEt₂]₄, and [CuN(i-Pr)₂]₄. We studied their lowest-energy excited states by measuring their phosphorescence spectra. We found that these tetramers behave similarly when it comes to their absorption and emission of light.