Abstract
The electrochemistry of ruthenium (Ru) etching in acidic solution containing cerium (IV) (Ce4+) has been investigated. Voltammograms were measured to determine the onset potentials of metal stripping and cathodic reduction of the oxidizing agent. Etch rates of blanket thin films of chemical vapour deposited Ru were measured using Rutherford backscattering spectrometry. Sheet resistance measurements of a thickness range of wet-chemically etched and as-deposited Ru thin films are compared. X-ray photoelectron spectroscopy was used to characterize post-etching residues. Using atomic force microscopy, the surface morphology of Ru after etching and removal of residues by rinsing with water or acid and ultrasonic agitation was studied. Compatibility of low-k dielectric material with the etchant has been assessed using Fourier transform infrared spectroscopy. UV–vis absorption spectroscopy was used to study the stability and absorption features of various Ce4+ compounds in sulphuric and methane sulphonic acid. Additionally, mixtures containing Ce4+ and Ce3+ were analyzed. In situ measurements during Ru etching show the conversion of the oxidizing agent to Ce3+.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.