InAlN/GaN-on-Si HEMTs with an InGaN Back Barrier for mm-Wave Applications

Abstract

We present InAIN/GaN-on-Si HEMTs with a 26 nm intrinsic GaN (iGaN) channel and a carbon-doped (cGaN) buffer separated by a thin 8 nmIn(0.12)GaN back barrier and a buried intrinsic GaN (biGaN) layer. Investigating the influence of varying the cGaN and biGaN layer thicknesses reveals the significance of introducing a biGaN layer to minimise buffer trapping and reduce the large-signal performance penalty. Large-signal characterisation at 28 GHz, with harmonic tuning up to the third harmonic, shows excellent metrics for 80 nm gate length devices, with a respective Gain, P-sat, PAE of 12.6 dB, 1.06 W/mm, and 50% at 6 V, and 10 dB, 2.6 W/mm, and 50% at 10 V, positioning them as strong candidates for further optimisation targeting FR2 user equipment applications.