Copper Layers Deposited on Aluminum by Galvanic Displacement

TitleCopper Layers Deposited on Aluminum by Galvanic Displacement
Publication TypeJournal Article
Year of Publication2011
AuthorsAi JH, Liu SP, Widharta NA, Adhikari S, Anderegg JW, Hebert KR
Journal TitleJournal of Physical Chemistry C
Date Published11
Type of ArticleArticle
ISBN Number1932-7447
Accession NumberWOS:000296685800032
Keywordsalkaline-solutions, dissolution, electrodeposition, HYDRIDE, IN-SITU, nucleation, silver, SUBSTRATE, surfaces, ultralarge-scale integration

Metallization layers nanometers to tens of nanometers thick are desirable for semiconductor interconnects, among other technologically relevant nanostructures. Whereas aqueous deposition of such films is economically attractive, fabrication of continuous layers is particularly challenging on oxidized substrates used in many applications. Here it is demonstrated that galvanic displacement can deposit thin adherent copper layers on aluminum foils and thin films from alkaline copper sulfate baths. According to scanning electron microscopy and quartz crystal microbalance measurements, the use of relatively low CuSO(4) concentrations produced films composed of copper nanoparticles overlying a uniform continuous copper layer on the order of nanometers in thickness. It seems that there are no precedents for such thin layers formed by aqueous deposition on oxidized metals. The thin copper layers are explained by a mechanism in which copper ions are reduced by surface aluminum hydride on Al during alkaline dissolution.

Alternate JournalJ. Phys. Chem. C