Comparative study of Cu precursors for 3D focused electron beam induced deposition

• Published in: Journal of the Electrochemical Society Vol. 151; no. 8; pp. C535 - C537
• Main Authors: LUISIER, A, UTKE, I, BRET, T, CICOIRA, F, HAUERT, R, RHEE, S.-W, DOPPELT, P, HOFFMANN, P
• Format: Journal Article
• Language: English
• Published: Pennington, NJ Electrochemical Society 2004
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; CVD; Scanning electron microscopy; Chemical stability; Monolayers; Copper compounds; Transition elements Compounds; Electron beam deposition
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1765680

The copper precursors bis-hexafluoroacetylacetonato-copper Cu(hfac)2, vinyl-trimethyl-silane-copper(I)-hexafluoroacetylacetonate (hfac)Cu(VTMS), 2-methyl-l-hexen-3-yne-copper-hexafluoroacetylacetonate (hfac)Cu(MHY), and dimethylbutene-copper(I)-hexafluoroacetylacetonate (hfac)Cu(DMB) are compared with respect to deposition rates and metal content obtained by focused electron beam induced deposition. Exposure was performed with 25 keV electrons in a Cambridge S100 scanning electron microscope equipped with a lithography system. Tip deposition rates increase with increasing precursor vapor pressure and range between 47 nm/s for (hfac)Cu(DMB) to about 4 nm/s for Cu(hfac)2. A decay of deposition rates with time, i.e., tip length, is observed. Electric 4-point measurements indicate an insulating behavior of deposited lines for all precursors. In contrast, Cu contents of up to 45-60 atom % were found by Auger electron spectroscopy in thin rectangular deposits using (hfac)Cu(DMB) and (hfac)Cu(VTMS) as precursors. A discussion in terms of monolayer coverage, completeness of precursor molecule dissociation, and precursor stability is presented.