Surface-selective chemical vapor deposition of copper films through the use of a molecular inhibitor

Shaista Babar, Elham Mohimi, Brian Trinh, Gregory S Girolami, John R Abelson

Research output: Contribution to journalArticle

Abstract

We report a simple process for the selective deposition of copper films on RuO2, while no Cu nucleation occurs on thermal SiO2 or porous carbon doped oxide (CDO). Using the precursor Cu(hfac)VTMS, selectivity is attained by adding a co-flow of excess VTMS to act as a growth inhibitor. With precursor alone, 52 nm of Cu grows on RuO2; on CDO or on thermal SiO2, nucleation is delayed such that 41 or 1.3 nm are deposited, respectively. Repeating the experiment with the co-flow of VTMS affords a 12 nm thick Cu film on RuO2 with roughness of 1.8 nm. But on CDO or thermal SiO2, the Cu deposition is only 0.10 or ∼0.04 nm, respectively. AFM scans of the CDO and SiO2 surfaces are identical to the bare substrates. The small quantity of Cu that is deposited must be finely distributed, presumably on defect sites; it can be etched to below the RBS detection limit using a co-flow of Hhfac and VTMS for few minutes at the end of the growth. The process window is wide: selective growth occurs for a range of VTMS pressures (0.5. 2.0 mTorr), growth times (up to 90 min), and growth temperatures (up to 180.C).

Original languageEnglish (US)
Pages (from-to)N60-N63
JournalECS Journal of Solid State Science and Technology
Volume4
Issue number7
DOIs
StatePublished - Jan 1 2015

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

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