AFM observation GaN grown on different substrates at low temperatures

The relationship between the substrate temperature and the morphology and properties of GaN was studied. By using the hydride chemical vapor deposition method, GaN films were deposited in different kinds of substrates, including sapphire, Si(111), Si(100), GaAs and GaP(111) both the P face and Ga face. The growth was performed at low temperatures below 700 °C. The film properties were characterized by XRD, Hall measurement, Cathodoluminescence (CL) and atomic force microscopy (AFM). It has been found that the temperature and nature of substrate materials affect the layer morphology. There is no relationship between the optical properties and layer morphology.