Deep level related to a two-dimensional electron gas region in Al _xGa _1-xN/GaN heterointerfaces

Deep-level transient spectroscopy (DLTS) measurements were performed on Al _xGa _1-xN/GaN heterostructures grown by using molecular beam epitaxy. The DLTS results show two deep levels, J ₁ and J ₂. The J ₁ peak is attributed to an electron trap related to a dislocation in a two-dimensional electron gas region at the Al _xGa _1-xN/GaN heterointerface and has an activation energy of E _c - 0.20 eV and a capture cross section of 4.4 × 10 ^-20 cm ^-2. The J ₂ peak is related to the point defect. These results provide important information on the electronic properties for improving the fabrication efficiencies of Al _xGa _1-xN/GaN heterostructure-based high-electron-mobility transistors.