{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T19:21:42Z","timestamp":1774380102488,"version":"3.50.1"},"reference-count":26,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2021,7,25]],"date-time":"2021-07-25T00:00:00Z","timestamp":1627171200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/CTM-CTM\/31953\/2017"],"award-info":[{"award-number":["PTDC\/CTM-CTM\/31953\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>The use of Ta\/TaN barrier bilayer systems in electronic applications has been ubiquitous over the last decade. Alternative materials such as Co-W or Ru-W alloys have gathered interest as possible replacements due to their conjugation of favourable electrical properties and barrier layer efficiency at reduced thicknesses while enabling seedless Cu electroplating. The microstructure, morphology, and electrical properties of Cu films directly electrodeposited onto Co-W or Ru-W are important to assess, concomitant with their ability to withstand the electroplating baths\/conditions. This work investigates the effects of the current application method and pH value of the electroplating solution on the electrocrystallisation behaviour of Cu deposited onto a Co-W barrier layer. The film structure, morphology, and chemical composition were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy, as well as photoelectron spectroscopy. The results show that the electrolyte solution at pH 1.8 is incapable of creating a compact Cu film over the Co-W layer in either pulsed or direct-current modes. At higher pH, a continuous film is formed. A mechanism is proposed for the nucleation and growth of Cu on Co-W, where a balance between Cu nucleation, growth, and preferential Co dissolution dictates the substrate area coverage and compactness of the electrodeposited films.<\/jats:p>","DOI":"10.3390\/nano11081914","type":"journal-article","created":{"date-parts":[[2021,7,25]],"date-time":"2021-07-25T22:07:00Z","timestamp":1627250820000},"page":"1914","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Seedless Cu Electroplating on Co-W Thin Films in Low pH Electrolyte: Early Stages of Formation"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5845-5698","authenticated-orcid":false,"given":"R\u00faben F.","family":"Santos","sequence":"first","affiliation":[{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2013Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3920-6511","authenticated-orcid":false,"given":"Bruno M. C.","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2013Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5788-4316","authenticated-orcid":false,"given":"Alexandre","family":"Ch\u00edcharo","sequence":"additional","affiliation":[{"name":"International Iberian Nanotechnology Laboratory, Av. Mestre Jos\u00e9 Veiga, 4715-330 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9875-6188","authenticated-orcid":false,"given":"Pedro","family":"Alpuim","sequence":"additional","affiliation":[{"name":"International Iberian Nanotechnology Laboratory, Av. Mestre Jos\u00e9 Veiga, 4715-330 Braga, Portugal"},{"name":"Centre of Physics, University of Minho, 4710-057 Braga, Portugal"}]},{"given":"Paulo J.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"International Iberian Nanotechnology Laboratory, Av. Mestre Jos\u00e9 Veiga, 4715-330 Braga, Portugal"},{"name":"Materials Science and Engineering Program, University of Texas at Austin, Austin, TX 78712, USA"},{"name":"Mechanical Engineering Department and IDMEC, IST University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4670-4516","authenticated-orcid":false,"given":"S\u00f3nia","family":"Sim\u00f5es","sequence":"additional","affiliation":[{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2013Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2894-771X","authenticated-orcid":false,"given":"Filomena","family":"Viana","sequence":"additional","affiliation":[{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2013Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3667-0562","authenticated-orcid":false,"given":"Manuel F.","family":"Vieira","sequence":"additional","affiliation":[{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2013Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,7,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1016\/j.surfrep.2016.03.002","article-title":"How to control solid state dewetting: A short review","volume":"71","author":"Leroy","year":"2016","journal-title":"Surf. 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