Download or read book Sol-Gel Derived Ferroelectric Thin Films for Voltage Tunable Applications written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferroelectric perovskite thin films for voltage tunable applications, namely (Ba, Sr)TiO3 (Barium Strontium Titanate or BST) and (Pb, Sr)TiO3 (Lead Strontium Titanate or PST), are synthesized via the so-called sol-gel route. While BST shows the tendency to severe film cracking, PST can be grown crack free onto platinised Si standard substrates and even directly onto SiO2, SiNx or bare Si. The growth kinetics of PST on platinised SiO2/Si and directly on SiO2/Si are studied in detail using X-ray diffractometry (XRD), scanning electron and atomic force microscopy, SEM and AFM respectively. It is shown that PST begins to crystallise at 500°C on Ti/Pt and 550°C directly on SiO2. After a thermal treatment of 650°C for 15 min both films are fully crystallised with random (100) and (110) orientation and a smooth surface. The dielectric properties, e.g. dielectric constant, loss and tunability, of PST 50/50 are measured using a standard Ti/Pt bottom electrode with Cr/Au top electrodes and a TiW/Cu bottom electrode on which the PST thin film was bonded with TiW/Cu top electrodes. The Cu/PST/Cu system shows an enhanced performance in terms of loss resulting in a larger device quality factor and a figure of merit (FOM) of 18.25 compared to 16.6 for the configuration using a Pt bottom electrode. The maximum tunability is 73% with an applied voltage of 35V and the dielectric constant at zero bias is ~ 420 with a loss