Lithium niobate thin films deposited on silicon substrates for SAW applications (surface acoustic wave)
Lin, Albert Jian
Rabson, Thomas A.
Master of Science thesis
Lithium niobate has a number of attractive piezoelectric and ferroelectric properties that have been exploited for several different applications. The main purpose of this work is to produce lithium niobate thin films on silicon substrates (with amorphous SiO$\sb2$ coating) and to make low insertion loss surface acoustic wave (SAW) devices. For SAW devices, the insertion loss mainly relates to the electromechanical coupling coefficient (K$\sp2$) of the materials. To get low insertion loss in SAW devices, we need use high K$\sp2$ materials. Among common piezoelectric materials, lithium niobate has the highest K$\sp2$ value. Theoretical curves of SAW properties of lithium niobate bulk crystals and films on SiO$\sb2$(amorphous)/Si(100) were obtained. Thin films of lithium niobate have been deposited on SiO$\sb2$(amorphous)/Si(100) substrates by rf magnetron sputtering. The film samples were structurally analyzed by x-ray diffraction (XRD). Lithium niobate XRD peaks (012), (104) and (110) were identified. Highly textured lithium niobate film samples with very good transparency and uniformity were obtained.
Engineering; Materials science; Electronics; Electrical engineering