Processing and characterization of lithium niobate thin films for ferroelectric nonvolatile memory applications
Rabson, Thomas A.
Master of Science
Both highly c-axis and randomly-oriented LiNbO3 thin films are grown on p-type Si (111) substrates by RF magnetron sputtering and metallo-organic decomposition (MOD), respectively. Ellipsometry, X-ray diffraction, AFM and SEM are used to analyze the structural quality of the deposited ferroelectric thin films, including thickness, crystallinity, stoichiometry and surface roughness. Metal-ferroelectric-semiconductor structures are fabricated and electrically characterized with polarization vs. electric field (P-E) and capacitance vs. voltage (C-V) measurements. Hysteresis curves based on polarization switching are observed, verifying the ferroelectricity of deposited LiNbO3 thin films. Comparison of different film growth mechanisms between these two deposition methods is made, and their effects on physical and electrical characteristics of the derived LiNbO3 thin films are discussed. RF magnetron sputtering is proved to be a more promising thin-film growth technique than MOD for ferroelectric nonvolatile memory applications.
Electronics; Electrical engineering