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Sol-gel processing was used for the fabrication of LiNbO3 thin-layers on semiconductors. Two different alkoxide systems were investigated (i.e., ethoxide vs. methoxyethoxide) to determine the role of solution chemistry on the evolution of structure in LiNbO3 layers. An alcohol exchange reaction, which produced lithium niobium methoxyethoxide, proved advantageous with respect to the amount of hydrolysis water content which could be added to give stable solutions. Spin-casting was used for the deposition of thin-layers which crystallized at 500 C on Si. The refractive index of sol-gel derived LiNbO3 was determined to be similar to sputtered or epitaxially grown films. Data are reported for the processing route and the material characteristics. Methoxyethanol based systems appeared to be more forgiving than ethanol based solutions for the fabrication of high-quality thin-layer devices.

X-ray photoelectron spectroscopy was used to study the thermal conversion of Li, Nb alkoxide derived thin layers on Si(100). Changes in the surface composition with temperature indicated a decomposition process involving lithium transport to the surface, lithium carbonate or oxycarbonate formation, and subsequent reaction to form lithium niobate. For comparison purposes, spectra were also obtained for a single crystal of lithium niobate and layers prepared from sol-gel derived lithium ethoxide and niobium ethoxide. Heat treatment of the individual precursors gave lithium carbonate (or oxycarbonate) and niobium oxide, respectively.