Growth of c-Axis-Oriented LiNbO₃ Films on ZnO/SiO₂/Si Substrate by Pulsed Laser Deposition for Surface Acoustic Wave Applications

Highly c -axis-oriented LiNbO 3 (006) thin films were successfully grown on SiO 2 /Si substrates with a ZnO buffer layer by XeCl excimer pulsed laser deposition (PLD). The as-deposited films were characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy to analyze their crystalline structure and surface morphology. The results show that the highly c -axis-oriented LiNbO 3 thin films of 2.5 µm thickness were successfully grown on SiO 2 /Si substrates with a ZnO buffer layer by PLD. The full width at half maximum intensity of the LiNbO 3 (006) peak of the sample fabricated under the optimum deposition conditions is only 0.18°. The center frequency of the LiNbO 3 /ZnO/SiO 2 /Si substrate with line width of 4 µm is 188 MHz, and the phase velocity is 3010 m/s, which is slightly lower than that of the 36° Y – X LiNbO 3 substrate.