A multi ion beam sputtering technique can be used to successfully fabricate ferroelectric lead zirconate titanate (PZT). This technique is very advantageous in that the ion beam current and voltage can be attuned which allows for the control of flux density and energy of sputtered materials. This technique also offers lower operating pressures during deposition, controllable deposition, and outstanding uniformity over larger areas, reproducibility, and localized plasma within an ion source. Ion beam sputtering is an excellent growth technique and been used extensively to deposit oxide films and semiconductors. But this method has been used mostly to deposit single element oxides and not multi element compounds such as ferroelectrics like PZT. This is most likely due to the lack of uniformity, reproducibility and control of stoichiometry with depositing multi elemental compounds.
An experiment was conducted at the Materials Research Laboratory, at Pennsylvania State University, University Park utilizing a multi ion beam technique to deposit PZT on various unheated substrates. In the experiment a multi ion beam sputtering system was utilized to sputter PZT from separate metals of Pb, Zr, and Ti. This system provides uniformity over large areas, and control over stoichiometry since PZT was broken into single elemental compounds. In the experiment the three metals targets, Pb, Zr, and Ti were placed on adjustable brackets. The brackets were designed to be flexible and adjustable so that they could be placed in any position with respect to the ion beam. Three primary ion sources were focused and adjusted with respect to the targets. The targets were placed a distance of about 11 to 16 cm from the ion source and a shutter was pla...
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...ed, but when the annealing time to 20 s the films maintained a pure perovskite phase. The conventional oven annealing process produced a mixture of pyrochlore and perovskite crystals at 600 ° C at an annealing time of 2 h. When the PZT films were annealed at 650 °C for 2 h all films assumed pure perovskite crystal structures. The Pb content also had an effect on the crystallization of the PZT film. It was determined that excess PZT increased crystallization toward the perovskite phase. Although excess Pb increase crystallization it worsens the morphology. PZT films deposited with excess Pb tend to have a rougher surface.
Multi‐ion‐beam reactive sputter deposition of ferroelectric Pb(Zr,Ti)O3 thin films
S. B. Krupanidhi, H. Hu, and V. Kumar
Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802