Citation:
C. Bertoni, D.E. Gallardo and S. Dunn, Electroforming processes for platinum nanoisland thin films, Thin Solid Films, Volume 495, Issues 1-2, EMRS 2005 Symposium E - Synthesis, Characterization and Applications of Mesostructured Thin Layers, 20 January 2006, Pages 29-35.
Abstract:
An investigation of the electroforming processes for platinum discontinuous thin
films is detailed. Current–voltage characteristics, for metal nanoislands
deposited by sputtering, were obtained in vacuum and air and typically showed
voltage-controlled negative resistance (VCNR) behaviour. The current maximum
shifted with the electrode separation. Electroforming under high current density
regimes was non-regenerative as samples showed irreversible resistance changes.
SEM examination of the film revealed a change in the metal microstructure. Such
modifications arise as a result of the current flowing through the film inducing
electro and thermal migration. Current-induced effects were studied by modelling
the metal nanoisland (MN) layer as an array of cubic cells. Plots of current
distribution showed that hot-spots develop along conductive paths.
Electromigration combined with resistive heating can lead to progressive
destruction of current channels at these hot-spots. Hence, current profiles and
SEM micrographs were interpreted as evidence of a ‘macroscopic’ electrical
breakdown of sample conduction due to microstructural modifications of the thin
film. The reduction of ohmic component and consequent resistive heating along
the current channels prevented the metal migration and stable current profiles
were obt