Lithium niobate thin films on diamond substrates for SAW devices.

摘要

Lithium niobate thin films have been grown on diamond/silicon substrates by metallo-organic decomposition and radio frequency (R. F.) magnetron sputtering. The surface acoustic wave (SAW) characterizations of the multilayer lithium niobate/diamond/silicon are calculated. The lithium niobate thin films as well as the diamond/silicon substrates are structurally analyzed using techniques such as Bragg X-ray diffraction, scanning electron microscopy, atomic force microscopy, electron microprobe, and Raman spectroscopy to determine their crystal structure, surface morphology and composition distribution. With the use of a lift-off photolithography planar process, surface acoustic wave filter devices on substrates such as lithium niobate single crystal plates, zinc oxide/diamond/silicon, and lithium niobate/diamond/silicon, are fabricated. Microwave characterizations, such as the frequency response, of these filters are measured, and their impulse response in the time domain are obtained by fast Fourier transformation. SAW activities for LiNbO₃/diamond/silicon structure are observed. Discussions about the results and further improvements are presented.