GaN on AlN ceramic substrate bonded wafers are engineered substrates that are used in the manufacture of high-performance electronic and optoelectronic devices. GaN, short for Gallium Nitride, is a wide bandgap semiconductor material that is known for its high electron mobility, high thermal stability, and high breakdown voltage, which makes it ideal for high-power and high-frequency applications. The AlN ceramic substrate provides excellent thermal stability and mechanical strength to the GaN epilayer. The bonding process involves depositing an AlN layer on a ceramic substrate and then bonding the GaN epilayer to the AlN layer. This results in a robust and reliable substrate for GaN device fabrication. Applications for GaN on AlN ceramic substrate bonded wafers include high-power microwave devices, high-efficiency power electronics, and high-brightness light-emitting diodes (LEDs).