Reproducible and uniform growth of GaN based HEMTs on 4 inch SiC by plasma assisted molecular beam epitaxy suitable for production

Abstract

Abstract We report on the progress of plasma assisted molecular beam epitaxy (PA‐MBE) of AlGaN/GaN based high‐electron‐mobility‐transistor (HEMT) structures towards a process suitable for production. A uniform growth process on SiC substrates with diameter up to 4 inch was developed with variations in thickness and composition of Δ d / d = ±1% and Δ x = ±0.5%, respectively, and an excellent run‐to‐run reproducibility. The device quality was evaluated after processing with a 4 inch technology. Processed wafers exhibit very good uniformity and yield. Identical performance of all transistors on the entire wafers with high power added efficiency (PAE) of 63%, power density of 6 W/mm, linear gain around 25 dB, and gate leakage currents below 10 µA/mm at 2 GHz and 50 V drain bias were achieved. Accelerated lifetime tests revealed promising long term stability.