Transfer of AlGaN/GaN RF-devices onto diamond substrates via van der Waals bonding

We present a new bonding process for gallium nitride (AlGaN/GaN) devices from Si onto diamond substrates. In our technology AlGaN/GaN-devices are transferred from silicon (Si) onto single (SCD) and polycrystalline diamond (PCD) substrates by van der Waals bonding. Load-pull measurements on Si and SCD at 3 GHz and 50 V drain bias show comparable power-added-efficiency (PAE) and output power (Pout) levels. Also, comparisons of 2x1 mm GaN-diodes on Si, PCD, and SCD reveal significantly increased power levels. In summary, we show a promising new GaN-on-diamond technology for future high power, microwave GaN-device applications.