Deep-level transient spectroscopy of GaN grown by electrochemical deposition and irradiated with alpha particles

Gallium nitride, which is used in modern electronic devices, is generally grown employing expensive epitaxial techniques. This study investigated the growth of GaN using electrochemical deposition and compared the use of two substrates, silicon (111) and indium tin oxide, under different conditions. Using different characterization techniques, it was found that the properties of the film depended on both the substrate and deposition conditions. X-ray diffraction demonstrated the presence of mainly hexagonal but also a small amount of cubic structures with crystallite sizes ranging from between 11 nm and 18 nm. Schottky diodes were fabricated on the thin films deposited on Si (111) and were characterized using I-V, C-V and DLTS measurements. The Schottky diodes had a rectification ratio of about 20, a I-V barrier height of 0.58 eV, a C-V barrier height of 1.18 eV and carrier density of 1.1 x 10(18) cm(-3). In the as-grown material, only one defect state at 0.32 eV below the conduction band was observed. However, after irradiation with high-energy alpha particles, four defect states at 0.10 eV, 0.20 eV, 0.42 eV and 0.51 eV were observed.