Thin Solid Films, Vol.518, No.10, 2839-2842, 2010
Dislocation reduction in nitride-based Schottky diodes by using multiple MgxNy/GaN nucleation layers
We present the characteristics of nitride-based Schottky diodes with a single low-temperature (LT) GaN nucleation layer and multiple MgxNy/GaN nucleation layers. With multiple MgxNy/GaN nucleation layers, it was found that reverse leakage current became smaller by six orders of magnitude than that with a conventional LT GaN nucleation layer. This result might be attributed to the significant reduction of threading dislocations (TDs) and TD-related surface states. From the double crystal X-ray diffraction and photoluminescence analyses, it was found that the introduction of multiple MgxNy/GaN nucleation layers could be able to effectively reduce the edge-type TDs. Furthermore, it was also found that effective Schottky barrier height (phi(B)) increased from 1.07 to 1.15 eV with the insertion of the multiple MgxNy/GaN nucleation layers. (C) 2009 Elsevier B.V. All rights reserved.
Keywords:Nitrides;Schottky diodes;MgxNy/GaN;Nucleation layers;Atomic Force Microscopy;Secondary-Ion Mass Spectroscopy;X-ray diffraction;Electrical properties and measurements