Electrical characterization of thin-film lithium niobate
Rabson, Thomas A.
Master of Science
The electrooptic properties of a thin film of lithium niobate were studied. The film was deposited on an n-type silicon substrate by RF sputtering. The short circuit photocurrent was measured as a function of time, and the voltage dependence of current and capacitance under light and dark conditions was measured. Photocurrents up to 16.1 pA were obtained with a light intensity of .5 mW/cm . With one exception, all photocurrent flowed from the A1 contact to the Si substrate. The current was linear for | Vapp | < .5 volts. At higher voltages, a thermal current was generated. It was found that the current required several minutes to reach its steady state value when the applied voltage was changed. The film was shown to possess some of the ferroelectric properties present in bulk crystals. Although no crystallographic studies have been done, the electrical measurements indicate that the LN film is polycrystalline.