A Heterogeneously-Integrated Ka-Band, N-Polar Gallium Nitride HEMT Amplifier

We demonstrate the heterogeneous integration of an 80-nm N-polar GaN HEMT fabricated on a silicon carbide wafer into a standard silicon wafer to realize a millimeter-wave amplifier that operates at 26 GHz with 19.8-dBm saturated power (Psat), 34% drain efficiency, and 8.0-dB peak gain. The assembly process can be readily adapted to other device technologies and provide a pathway to rapidly incorporate diverse compound semiconductors into silicon CMOS processes for millimeter-wave systems.