Piezoelectric thin film deposition: Novel self-assembled island structures and low temperature processes on silicon

Lead zirconate titanate Pb(Zr1-yTiy)O3 is a material that is known for its high piezoelectric and ferroelectric properties. Thick and thin films of lead zirconate titanate (PZT) have been repeatedly used in a variety of piezoelectricity or piezoresistivity based sensors such as biosensing cantilevers (Park et al., 2005a) and pressure sensors (Maluf & Williams, 2004). PZT is one of many ceramic compounds with a general ABO3 representation. Zirconium (Zr) and titanium (Ti) are B-site dopants of the compound and the ratio of Zr/Ti can alter the film properties such as the dielectric tenability (Yu et al., 2004). Certain A-site dopants (in place of a fraction of the lead atoms present in A-site locations) have been found to increase certain properties and introduce other properties. Examples of these are (i) lanthanumdoped PZT (PLZT) is known for enhanced electro-optic behaviour (Tunaboylu et al., 1998); (ii) stannum-doped PZT and niobium-doped PZT (PNZT) are known to exhibit shape memory behaviour, a property not exhibited by PZT (Yu & Singh, 2000); and (iii) the compound of interest in this chapter strontium-doped PZT (PSZT) has been reported to have improved piezoelectric, ferroelectric, dielectric tunability, and pyroelectric (infra-red radiation sensors by thermal effects) behaviour (Bedoya et al., 2000; Zheng et al., 2002; Araujo & Eiras, 2003; Yu et al., 2004).