Room-temperature quasi-direct bonding of LiNbO₃ and SiC wafers using modified surface activated bonding method

Abstract We have been developing a modified surface activated bonding (SAB) method as an alternative approach to the conventional SAB method. The modified SAB method with ion beam bombardment was used to achieve quasi-direct bonding of LiNbO 3 and SiC wafers at room temperature. The measured bond strength was greater than 20 MPa, which is sufficient to endure the post-bonding processes for device fabrication, and the effectiveness of the proposed method when compared to the conventional SAB method was experimentally verified. The results provide evidence that LiNbO 3 and SiC wafers can be strongly bonded at room temperature and demonstrate the potential for the future fabrication of heterogeneous LiNbO 3 /SiC devices including temperature-compensated and heat-dissipated surface acoustic wave filters.