PROCESS-PROPERTY CORRELATIONS OF EXCIMER-LASER ABLATED BISMUTH TITANATE FILMS ON SILICON

Bismuth titanate thin films were deposited by the excimer laser ablation technique directly onto bare silicon substrates, SiO2 and Si3N4 coated silicon. The impact of process parameters such as gas pressure, laser fluence, processing temperature, and the presence of an oxygen plasma were studied with regards to the ferroelectric-semiconductor interface. The density of interfacial surface state (N(ss)) at the flatband voltage was found to be on the order of 10(12)-10(14) eV-1 cm-2. Hysteretic capacitance-voltage data indicated charge injection from the substrate was the dominant mechanism, masking any polarization mode. Films deposited on SiO2 coated silicon did, however, exhibit polarization type switching.