Highly c-Axis-Oriented Monocrystalline Pb( Zr, Ti)O3 Thin Films on Si Wafer Prepared by Fast Cooling Immediately After Sputter Deposition

We successfully developed sputter deposition technology to obtain a highly c-axis-oriented monocrystalline Pb(Zr, Ti)O-3 (PZT) thin film on a Si wafer by fast cooling (similar to-180 degrees C/min) of the substrate after deposition. The c-axis orientation ratio of a fast-cooled film was about 90%, whereas that of a slow-cooled (similar to-40 degrees C/min) film was only 10%. The c-axis-oriented monocrystalline Pb(Zr-0.5, Ti-0.5)O-3 films showed reasonably large piezoelectric coefficients, e(31,f) = similar to-11 C/m(2), with remarkably small dielectric constants, epsilon(r) = similar to 220. As a result, an excellent figure of merit (FOM) was obtained for piezoelectric microelectromechanical systems (MEMS) such as a piezoelectric gyroscope. This c-axis orientation technology on Si will extend industrial applications of PZT-based thin films and contribute further to the development of piezoelectric MEMS.