Noncontact probing method for estimation of ferroelectric properties of PbTiO3-based films for microelectromechanical systems

作者：Ehara Yoshitaka; Utsugi Satoru; Nakajima Mitsumasa; Chentir Mohamed Tahar; Yamada Tomoaki; Iijima Takashi; Nishida Ken; Yamamoto Takashi; Funakubo Hiroshi^*

来源：Journal of Materials Research, 2012, 27(11): 1430-1435.

DOI：10.1557/jmr.2012.100

Raman scattering spectra and ferroelectric properties of epitaxial tetragonal Pb(Zr, Ti)O-3 were investigated for polar axis-oriented thin films with various Zr/(Zr + Ti) ratios and by changing the ratios from 0 to 0.50 at different measurement temperatures. The chosen films in the thickness range of 1-2 mu m present the advantage of showing small residual strain. The E (TO) modes were successfully isolated using cross-polarization configurations, while A(1) (TO) and B-1 modes were activated using parallel polarization configurations. Systematic changes in Raman peak positions were observed with changes in the Zr/(Zr + Ti) ratios at different measurement temperatures. It was found in both cases that the tetragonal distortion (c/a-1) and the value of square of spontaneous polarization (P-s(2)) linearly increased with increasing omega(2)[A(1)(1TO)], where a and c are the lattice parameters of a and c-axes. This indicates that monitoring A(1)(1TO) mode is efficient as a characterization method of ferroelectricity. It can also be used as a novel nondestructive process check or reliability assessment technique during fabrication of microelectromechanical systems (MEMS) using piezoelectric materials.

• 出版日期2012-6