MULTI-TARGET REACTIVE SPUTTER DEPOSITION OF LEAD-ENRICHED Pb(Zr,Ti)O₃ THIN FILMS

Abstract

Self-polarized Pb(Ti,Zr)O 3 (PZT) thin films deposited under lead-enriched conditions by multi-target reactive sputtering at low substrate temperatures are characterized by the presence of tetravalent lead occupying lattice Zr-sites. The optical properties of Pb(Pb x Zr y−x Ti 1−y )O 3 thin films of two composition x = 0.10, y = 0.31 and x = 0.29, y = 0.65 were investigated. Absorption coefficients in the visible spectra range were determined by Variable Angle Spectroscopic Ellipsometry. The presence of tetravalent lead was found to introduce structural disorder resulting in the broadening of the exponential absorption tail.

Large area deposition of Pb(Zr,Ti)O3 thin films for piezoelectric MEMS devices

“…The lattice constants derived from the XRD pattern were a≈0.39 nm, b≈0.375 nm, and c≈1.3 nm. Thus, the lattice parameter c is in good agreement with the lattice plane spacing obtained [15] in the HRTEM image. Obviously, lead-enriched interface layers near the ZrO 2 /PZT interface favor Pb 2 (Zr,Ti)O 4 nucleation.…”

“…The corresponding lattice spacings were 0.4055, 0.2327, 0.2896, and 0.2849 nm, respectively. Figure 3 compares the effective absorption coefficient of a Pb(Pb 0.31 Zr 0.28 Ti 0.41 )O 3 film deposited at 580°C onto a ZrO 2 buffer layer with the absorption behavior of an Pb (Pb 0.10 Zr 0.21 Ti 0.69 )O 3 film deposited onto a platinized silicon wafer [15]. Both samples show a pronounced Urbach behavior.…”

“…Both samples show a pronounced Urbach behavior. Recently, we have shown that the increase of the Urbach tails of smooth films is caused by an increasing disorder introduced by tetravalent lead [15]. Here, we have to take into account also the different surface roughness.…”

Nondestructive testing of ferroelectrics by thermal wave methods

“…Pb(Pb 0.10 Zr 0.21 Ti 0.69 )O 3 thin films were deposited by multi-target reactive sputtering at TU Dresden [25]. Commercially available LiTaO 3 crystals (NEL CRYSTAL Co. Ltd., Fukushima, Japan) were thinned down up to a thickness of 40 µm by polishing and further thinned down in the active area of pyroelectric elements up to 4 µm by ion beam etching [26].…”