PREPARATION OF BIAXIALLY ALIGNED CUBIC ZIRCONIA FILMS ON PYREX GLASS SUBSTRATES USING ION-BEAM-ASSISTED DEPOSITION

Yttria stabilized zirconia films were deposited using ion-assisted, el ectron beam deposition (IBAD) on pyrex glass substrates heated to 600- degrees-C. Films deposited under these conditions without IBAD exhibit fiber texture such that preferred (100) orientation exists perpendicu lar to the substrate. The orientation of the films has been studied as a function of ion bombardment angle, deposition rate, ion current den sity, and ion beam energy. Films deposited with IBAD at bombardment an gles of less than 63-degrees display strong (100) preferred orientatio n perpendicular to the substrate. Films having ion to atom ratios of 0 .05 exhibit (220) biaxial alignment in the plane of the film. Best res ults were achieved for films with deposition rates of 2.4 angstrom/s, beam energies of 75 eV and ion fluences of 18 muA/cm2. Increasing the beam energy to 300 eV increases the concentration of wire texture in t hese films. Films deposited at higher ion/atom ratios (0.11 and 0.25) produce films with alignments highly dependent on the angle of ion bom bardment. Processing conditions have been shown, therefore, to effect absolute orientation, and not just the quality of the pre-existing ori entation. The microstructures of the biaxially aligned films have been studied and this has allowed for a clarification of the growth mechan ism of these films. A growth instability of the differing orientations during ion bombardment is shown to cause in-plane alignment rather th an preferential etching of misoriented nuclei.