Thin Titanium Nitride Films Deposited using DC Magnetron Sputtering used for Neural Stimulation and Sensing Purposes

Abstract

n recent times Platinum (Pt), Iridium (Ir), Iridium oxide (IrO) and Platinum-Iridium (Pt-Ir) are the favorable microelectrode materials. They show excellent electrical and mechanical properties suitable for neural stimulation and sensing/recording purposes. But their long term stability and performance is still in question especially working in conductive saline environment. Titanium Nitride (TiN) is advantageous than the mentioned noble metals used as microelectrode material for nerve stimulation and sensing. TiN films are generally used in biomedical implants due to their good mechanical and high corrosion resistance with extreme biocompatibility. Here we talk over the capabilities of sputtered TiN material as a microelectrode material with respect to its mechanical and electrical properties. Also, we discuss the initial results for sputtered TiN layers and its surface properties suitable for electrical stimulation and sensing neuronal activity. TiN was chosen because it readily lends itself to reactive sputtering method and provides significant charge injection rates 23 mC/cm2 with excellent corrosion and biocompatibility properties. Titanium (Ti) and TiN thin films of 200 nm thick were deposited by DC magnetron sputtering process on plain silicon substrates. Initial AFM and XRD characterization study was carried to study the crystal structural properties of these thin films.