Synthesis and Characterization of Pb(Zr, Ti)O-Pb(Nb, Zn)O Thin Film Cantilevers for Energy Harvesting Applications

A complete analysis of the morphology, crystallographic orientation, and resulting electrical properties of Pb(Zr 0.53 ,Ti 0.47 ) Pb(Nb 1/3 , Zn 2/3 )O 3 (PZT-PZN) thin films, as well as the electrical behavior when integrated in a cantilever for energy harvesting applications, is presented. The PZT-PZN films were deposited using sol-gel methods. We report that using 20% excess Pb, a nucleation layer of PbTiO 3 (PT), and a fast ramp rate provides large grains, as well as denser films. The PZT-PZN is deposited on a stack of TiO 2 /PECVD SiO 2 /Si 3 N 4 /thermal SiO 2 /Poly-Si/Si. This stack is designed to allow wet-etching the poly-Si layer to release the cantilever structures. It was also found that the introduction of the poly-Si layer results in larger grains in the PZT-PZN film. PZT-PZN films with a dielectric constant of 3200 and maximum polarization of 30 μ C/cm 2 were obtained. The fabricated cantilever devices produced ~ 300–400 mV peak-to-peak depending on the cantilever design. Experimental results are compared with simulations.