Direct bonding of LiNbO3 and GaAs at room temperature by using activated Si atom layer.

Heterogeneous integration of LiNbO 3 and GaAs at room temperature has been achieved by using an activated Si atom interlayer, which demonstrate effectiveness in the fabrication of GaAs based LiNbO 3 wafer. By using the activated Si atom interlayer as the adhesive layer, 4-inch LiNbO 3 wafer is successfully directly bonded to the surface of GaAs wafer. The wafer bonding rate reaches over 95%. After bonding, the LiNbO 3 /GaAs bonding pair is cut into 10 × 10 mm2 square bonded chips. After annealing, the maximum bonding strength of square bonded chips exceeds 22 MPa. This means that the bonding strength of LiNbO 3 /GaAs wafer can be comparable to that of bulk materials. The characterization results of the bonding interface confirm that the intermediate amorphous Si layer is effective in improving the bonding strength and quality of LiNbO 3 /GaAs heterojunction. Heterogeneous integration of LiNbO 3 with GaAs and other Ⅲ-Ⅴ compound semiconductor materials is conducive to reducing the area occupied by optical communication platforms and improving the overall efficiency of devices. • 4 inches high-quality LiNbO 3 /GaAs heterostructure was prepared by Si atom intermediate layer. • The bonding mechanism of LiNbO 3 /GaAs was analyzed. • The bonding strength of LiNbO 3 /GaAs is 22 MPa respectively. This is the best known result. • The surface chemical states of LiNbO 3 , GaAs, Si deposition and debonding surface were characterized by XPS spectrum. [ABSTRACT FROM AUTHOR]