Polymer‐based route to ferroelectric lead strontium titanate thin films

Abstract

Ceramic films with high values of ferroelectricity, piezoelectricity, and dielectricity with perovskite structure, like lead zirconate titanate (PZT, PbZrxTi1‐xO3), lead strontium titanate (PST, PbxSr1‐xTiO3), and barium strontium titanate (BST, BaxSr1−xTiO3), are subjects of intensive research due to their use in sensors, energy harvesters, capacitors, and FeRAMs. Here a novel, simple way to produce micropatterned perovskite PST thin films on silicon substrates by a polymer‐based direct UV‐lithography process is presented. By acrylic acid modification of PST precursor sols it is possible to generate photosensitive metal organic PST precursor xerogel films by spin‐coating and subsequently drying on silicon wafers. These films can be patterned by UV‐lithography and developed with organic solvents. The resulting patterned gel films can be crystallized in air via rapid thermal annealing. The obtained perovskite thin ceramic films are polycrystalline and fine grained. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40901.

Manufacturing of membranes by laser ablation in SiC, sapphire, glass and ceramic for GaN/ferroelectric thin film MEMS and pressure sensors

“…The PST films were manufactured using a polymer-based deposition and patterning direct UV-lithographic process. We reported this process in detail in a publication (Benkler et al 2014). Due to the simple sol synthesis and the straightforward process, this method is an interesting alternative to other deposition and patterning processes.…”

“…It was shown that 4H-SiC 80 µm thick diaphragms can be fabricated five times faster with laser ablation in comparison to (RIE) (Vanko et al 2013). We now also investigate ferroelectric thin films as they can be deposited and micro-patterned by a direct UVlithography method after the ablation process for a specific membrane design (Benkler et al 2014). The risk to harm or damage the function of thin films can be eliminated by that fabrication procedure.…”