Electrochemical Society, Inc.;The Electrochemical Society
摘要:
摘要： In situ scanning tunneling microscopy (STM) was used to study copper deposition at vacancy defects on a copper thin film under potentiostatic conditions at −0.20 V (vs. Ag/AgCl) in a formula containing sulfuric acid, chloride, polyethylene glycol (PEG), and bis-3-sodiumsulfopropyl-disulfide (SPS) - the widely used mixture to facilitate Cu superfilling at recessed features in semiconductor processing. The vacancy island measuring ∼70 nm wide and 12 nm deep sat in the middle of a facetted surface structure at the beginning. Cu deposit nucleated mainly at the rim of the vacancy and grew into stacked Cu(111) facets. These local pyramidal Cu stacks could restructure into wider Cu(111) terraces by transferring Cu atoms rapidly from higher to lower planes. Voltammetric results showed that Cu deposition was suppressed in a plating bath containing 1 mM KCl + 88 μM PEG8000 + 10−7 M SPS. Steps with sharp edges bunched in the course of Cu deposition. The vacancy island was filled with Cu deposit assuming smooth terraces with sharp step edges aligned mainly in the 〈121〉 directions of the Pt(111) electrode, suggesting crystalline packing in the Cu deposit. Atomic-resolution STM imaging revealed a hexagonal array presumed to be the (√3 × √3)R30° - Cl− adlattice. 其他題名： J. Electrochem. Soc 出版者： The Electrochemical Society 出版日期： 2013-01 出處： Journal of The Electrochemical Society, 2013-01, Vol.160 (12), p.D3295-D3299 資源來源： Institute of Physics Journals 版權： 2013 The Electrochemical Society 識別號： ISSN: 0013-4651 識別號： EISSN: 1945-7111 識別號： DOI: 10.1149/2.049312jes
