In this study we successfully demonstrate a method for AgAu diffusion wafer bonding. We were able to achieve a high-melting-point bonding interface at a relatively low bonding temperature of 150°C. The AgAu interdiffusion coefficient is defined against the Au content. Au atoms have a faster diffusion rate in the Ag matrix layer, which causes the AgAu interface to move toward the Au side over time. The use of this method of AgAu diffusion bonding makes the fabrication of high-power thin- GaN light-emitting diode chips on Si wafers a feasible possibility.