Surface Activated Bonding of LiNbO3 and GaN at Room Temperature

In this study, we report room-temperature wafer bonding of a GaN and a LiNbO3 (LN) using a surface activated bonding (SAB) method. The modified SAB using Fe-containing Ar ion beam bombardment demonstrated the stronger bond strength of a GaN and a LN than the standard SAB using Ar fast atom beam bombardment. As the result of a dicing test, the bonded wafer using modified SAB method was successfully cut into 1 x 1 mm(2) dies without interfacial debonding owing to the applied stress during dicing. This result shows a strong bond strength which may be sufficient for device applications. It was found that Fe nanolayer deposited during ion beam bombardment appears to work well as an adhesive and form a strong bond between a negative surface of LN and a Ga-face of GaN.