Formation of Pb0.6Sr0.4(Ti0.97Mg0.03)O2.97 thin films on assembled bottom electrodes with titanium silicide nanowires

• The TiSi nanowires/Ti5Si3 thin film is prepared by a continuous two-step method.
• The TiSi/Ti5Si3 bottom electrode makes the preparation temperature of PST decrease.
• The TiSi/Ti5Si3 electrode contributes the increase of permittivity of PST thin film.
• The tunability of PST/TiSi/Ti5Si3 is improved to 2.5 times of that of PST/ITO.

Multi-layered bottom electrodes constituted by conductive Ti5Si3 thin films with and without TiSi nanowires were prepared on glass substrates by Atmosphere Pressure Chemical Vapor Deposition (APCVD) method. Pb0.6Sr0.4(Ti0.97Mg0.03)O2.97 (PST) thin films were deposited on the Ti–Si bottom electrodes by Radio-frequency Magnetron Sputtering Method. The morphology and phase structure of the PST thin films were observed and identified by FE-SEM and XRD, respectively. The dielectric properties of the PST thin films deposited on Ti–Si substrates were measured by Agilent 4294A Impedance Analyzer. Results show that the formation ability of the PST thin films can be reinforced by increasing crystallinity of Ti5Si3 thin films and increasing amount of TiSi nanowires. The preparation temperature of the PST thin films deposited on Ti5Si3 and TiSi-nanowire/Ti5Si3 bottom electrodes decreases by 75 °C and 98 °C, respectively, compared with the situation on ITO/glass substrate. The permittivity of the PST thin films deposited on TiSi-nanowire/Ti5Si3 bottom electrode is about 4 times higher than that deposited on ITO. The lowest dielectric loss of PST/TiSi-nanowire/Ti5Si3 thin films is <0.1 within a wide frequency range till 10 MHz, exhibiting impressive frequency stability compared with that deposited on ITO. High capacitance and high tunability also occur in PST/TiSi-nanowire/Ti5Si3 thin films. The tunability of the PST thin films is about 2.5 times higher on TiSi-nanowire/Ti5Si3 bottom electrode than that on ITO bottom electrode.