Processing and properties of high aspect ratio ferroelectric structures

High aspect ratio (/spl ges/50:1) ferroelectric structures are potentially applicable in areas such as tunable photonic devices, sensors and actuators. In this work high aspect ratio structures of Pb(Zr/sub x/, Ti/sub 1-x/)O/sub 3/, and LaNiO/sub 3//Pb(Zr/sub x/,Ti/sub 1-x/)O/sub 3//LaNiO/sub 3/ tri-layers were prepared by vacuum infiltration of meso-porous Si templates. Pyrolysis was done at 300/spl deg/C for 2 min. Reactive ion etching followed by XeF/sub 2/ isotropic Si etching was utilized to release the embedded PZT structures from the Si template. The released structures were annealed at 700/spl deg/C for 1 min. in order to induce crystallization. These 2D ferroelectric photonic structures exhibited a TE-mode band gap in the infrared region between 4.0 - 4.4 microns in wavelength, which was found to be consistent with the theoretical photonic band gap calculations.