| 초록 |
Piezoelectric thin films have been widely investigated for their applications in various microelectromechanical systems (MEMS), such as microsensors and microactuators. Lead zirconate titanate [Pb(Zr,Ti)O3, PZT] is one of the most popular materials because of its superior piezoelectric properties. So, PZT thin films have been studied as a key material for piezoelectric MEMS. However, PZT-based piezoelectric materials contain toxic lead, making it important to realize lead-free piezoelectric materials with high piezoelectric properties comparable to those of PZT, even in the form of thin films. Most of the work on lead-free ferroelectrics is related to materials from the alkaline niobate (K,Na)NbO3 (KNN) and the (Bi,Na)TiO3 (BNT) system. To develop the MEMS device using lead-free materials, the KNN and BNT-based materials have to be prepared in the thin film form, and successively the KNN and BNT-based thin films should be microfabricated by using photolithograph and etching process. In this study, we deposited the KNN and BNT-based thin films on Pt/TiO2/SiO2/Si substrates by using sol-gel method and measured their piezoelectric properties. We propose a fabrication method not only develop piezoelectric MEMS devices, but also to evaluate the piezoelectric characteristic in the KNN and BNT-based thin films. |
