Growth of Millimeter wave AlN/GaN Heterostructures by MOCVD

•GaN/AlN/GaN HEMT heterostructures were grown on 100 mm semi-insulating SiC substrates by MOCVD.•Growth temperature will influence the crystalline quality, surface morphology and electrical properties.•GaN cap growth temperature will influence the residual stress state and electrical properties of heterostructures.•Superior power performance was achieved in G-band.