Influence of the process parameters on the growth of YSZ-layers prepared by ion beam assisted deposition (IBAD)

Cubic yttria stabilized zirconia (YSZ) thin films were grown on amorphous quartz, r-plane sapphire and stainless steel substrates by ion beam sputtering from a planar target under simultaneous ion bombardment (IBAD) during film growth and sputtering employing the inverted cylindrical magnetron (ICM) gun. The formation and modification of preferred orientations was studied by X-ray diffraction and TEM investigations as a function of different deposition parameters like substrate temperature, total pressure, deposition rate, ion beam energy and current, A preferred (100)-orientation could be achieved on untextured substrates by ICM-deposition at substrate temperatures above 800 degrees C and by IBAD without external heating of the substrates, In-plane orientation of YSZ films on untextured substrates was only achieved with IBAD for an ion impact angle as between 30 degrees and 70 degrees, For a(s) = 55 degrees the best mosaic spread was observed. The observation of significantly smaller texture distribution widths for epitaxially post-deposited material than measured at the basic YSZ buffer layer was found to be due to a gradual improvement of YSZ growth under inn bombardment with increasing layer thickness.