Investigation of the inserted LT-AlGaN interlayer in AlGaN/GaN/AlGaN DH-FET strucutre on Si substrates

A novel AlGaN/GaN/AlGaN double-heterostructure field effect transistor (DH-FET) structure with an inserted LT-AlGaN interlayer grown on 150 mm Si substrate has been studied. The DH-FET structure has been characterized by transmission electron microscopy (TEM), secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD). It is found that the inserted LT-AlGaN interlayer can further induce the compressive stress to compensate the tensile stress. Furthermore, the inserted LT-AlGaN interlayer acts as a dislocation filter to reduce threading dislocation propagation. These results indicate that the inserted LT-AlGaN interlayer plays an important role in the novel DH-FET structure.