TAILORING THE DIELECTRIC-PROPERTIES OF HFO2-TA2O5 NANOLAMINATES

Dielectric thin films applicable, for instance, as insulating layers i n electroluminescent display devices have been studied. In order to im prove dielectric characteristics HfO2-Ta2O5 nanolaminates were prepare d by atomic layer epitaxy at 325 degrees C. The nanolaminates were eva luated in capacitance and current-voltage measurements. By optimizing the layer thicknesses in the nanolaminate structures the dielectric pr operties, especially leakage current densities, could be tailored rema rkably. The best nanolaminates showed charge storage factors improved up to 8 times when compared with those of the single oxide films. The presence of nanosize crystallites of monoclinic and metastable tetrago nal HfO2 was observed by x-ray diffraction analysis. (C) 1996 American Institute of Physics.