GAN-on-Si HEMTs for 50V RF applications

In this work we report on the fabrication and characterization of GaN-on-Si HEMTs for 50V RF applications at 2 GHz. Good wafer uniformity over the main DC parameters and leakage current levels below 10 μA/mm up to 100V were obtained on 4-inch Si substrate. Moreover, thanks to low RF loss at the Si substrate, a PAE close to 50% was measured on 1 mm devices by means of CW load-pull measurements at 50V/2GHz. The associated output power was 3.7W/mm, which was within the targeted value considering package and reliability constraints on the maximum allowable operating junction temperature. Results from on-wafer reliability tests consisting in constant current stress at 50V and off-state step stress up to 100V, both performed at an ambient temperature of 150°C, are also reported.