A comparison of Pd and Au electrodes-based LiNbO3 surface acoustic wave devices

作者：Liu, Bo; Mohammad, Mohammad Ali; Wang, Dan-Yang; Tian, Xiang-Guang; Tao, Lu-Qi; Yang, Yi; Ren, Tian-Ling^*

来源：Modern Physics Letters B, 2016, 30(32-33): 1650349.

DOI：10.1142/S0217984916503498

• Surface acoustic wave devices
• lithium niobate
• LiNbO3
• Pd electrode
• Au electrode

We report the comparison of electrode metals for LiNbO3 surface acoustic wave (SAW) devices. Palladium (Pd) was systematically studied as a SAW electrode metal for the first time, compared with gold (Au). Simulations were first conducted to gain an understanding of the differences of the materials and the metallization ratio. Two sets of identical SAW devices were then fabricated using Au and Pd as electrodes with different electrode widths and same SAW period. The insertion losses, types of resonance mode, the resonance frequencies, peak amplitudes, quality factors and trends with different metallization ratios were systematically compared and analyzed. We found that Pd electrode devices only exhibit the parallel resonance frequency and have higher resonance frequency for both the first-order and third-order harmonics. Au electrode devices tend to have a smooth response and a quality factor two times higher than Pd. Both Pd and Au electrode devices have nearly identical electromechanical coupling coefficients, and the quality factor and third-order harmonics both improve with increasing metallization ratio.

• 出版日期2016-11-30
• 单位清华大学