GaAs on AlN bonded wafers are engineered substrates that are used in the production of high-performance electronic devices. GaAs (gallium arsenide) is a compound semiconductor material that is known for its high electron mobility and high power-handling capability, making it suitable for use in high-frequency electronic devices, such as microwave and millimeter-wave transistors, high-speed digital circuits, and optoelectronics. AlN (aluminum nitride) is a wide-bandgap semiconductor that is known for its high thermal stability, high electrical insulation, and high thermal conductivity, making it an ideal substrate for GaAs devices that require high heat dissipation.
Bonding GaAs to AlN wafers involves depositing a thin layer of GaAs on top of a substrate made of AlN, and then bonding the two layers together through a process such as direct wafer bonding, metal bonding, or anodic bonding. This produces a GaAs/AlN heterostructure that offers the high performance of GaAs combined with the thermal stability and thermal conductivity of AlN, which helps to reduce the thermal resistance and increase the reliability of the device.