Factors Influencing the Variation of Surface Acoustic Wave Velocity in Lithium Tetraborate

Comparison of the resonance frequency of surface acoustic wave (SAW) resonators fabricated on defect-free and highly defective lithium tetraborate wafers was attempted. The intrinsic variation of SAW velocity due to crystal defects, impurities and chemical compositional inhomogeneities for lithium tetraborate wafers is smaller than +/-0.011%. In addition, the variation of SAW velocity in a wafer is influenced by the device fabrication process rather than the lithium tetraborate substrate quality.