Growth and processing of gallium nitride at high temperatures in an ultra high-pressure reactor furnace

We developed novel high-pressure techniques for the producing and processing gallium nitride (GaN) at elevated temperatures using a specially designed high-pressure reactor furnace. By working at high ambient pressures, we can suppress the tendency of GaN to chemically dissociate at elevated temperatures. Thus we can affect the growth of small crystals and promulgate microstructural changes in films grown on sapphire substrates via other techniques.; GaN crystals were grown and films annealed in the high pressure furnace and results investigated using a wide variety of qualitative and quantitative analytical characterization techniques including scanning electron microscopy (SEM), x-ray diffraction (XRD), micro-Raman spectroscopy, atomic force microscopy (AFM), optical profilometry, Auger electron spectroscopy (AES), cathodoluminescence (CL) and photoluminescence spectroscopy (PL), and energy dispersive x-ray spectroscopy (EDS).