Electrodeposition of platinum metal on TiN thin films

Electrodeposition of platinum metal from a chloride-based platinum electroplating bath at 35 °C onto high quality titanium nitride electrodes produced by standard microfabrication techniques has been demonstrated and characterised using electrochemical methods and scanning electron microscopy. When using a relatively simple two potential step electroplating procedure, it is possible to produce good quality deposits which are both adherent and metallic in appearance, without the need for electrode pre-treatment. Cyclic voltammetric analysis of these electrodeposited Pt/TiN films in dilute sulfuric acid yields voltammograms with features characteristic of bulk polycrystalline platinum electrodes. Voltammetry in potassium ferricyanide yields reversible voltammograms, indicating the good electrical conductivity of and connectivity between the deposited Pt and the TiN substrate and hence the absence of any significant resistive surface titanium dioxide or oxynitride film. This process is compatible with the production of platinum array electrodes, which can be integrated with silicon based microelectronic circuitry to produce array based sensors and biosensors.