GaN on Si3N4 bonded wafers are composite substrates that are commonly used in the semiconductor industry. They are typically created by bonding a thin layer of GaN to a Si3N4 substrate. The GaN layer provides a high-quality template for the growth of other semiconductor materials, such as gallium nitride (GaN) and aluminum nitride (AlN), which are used in the fabrication of high-performance electronic and optoelectronic devices. The Si3N4 layer provides mechanical support and electrical insulation for the GaN layer. These composite wafers are typically manufactured using wafer bonding techniques, such as direct wafer bonding or metal-mediated wafer bonding, followed by a thinning and polishing step to achieve the desired thickness and surface finish.