Group III-nitrides, and in particular, aluminum nitride (AIN), gallium nitride (GaN), and indium nitride (InN) make up a class of compound semiconductors with direct bandgaps ranging from 1.2 electron volts to 6.2 electron volts (eV). They afford a broad range of applications including light emitting diodes (LED's) and laser diodes (LD's) emitting from the visible to the ultraviolet (UV) portions of the electromagnetic spectrum, radiation detectors, and high power, high frequency electronic devices capable of operating at high temperatures, and in hostile chemical environments. Materials studied in this work were grown on silicon substrates, Si(111) by Molecular Beam Epitaxy (MBE) under a broad range of growth parameters and characterized using X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), Photoluminescence (PL), and four-point probe resistivity measurements. Growth began with deposition of 0.3 monolayer (ML) of Al on the Si(111)7x7 surface leading to fully passivated Si(111) [root of]3x[root of]3-Al surface. Next, an AIN buffer layer and then the GaN layers were deposited. X-ray measurements indicated growth of single-crystalline hexagonal GaN(001) while PL measurement demonstrated a peak position corresponding to bulk hexagonal-GaN. Sample morphology and resistivity showed a strong dependence on growth conditions. The layer RMS roughness increased with increasing thickness for samples grown with low atomic-nitrogen (N) to molecular N ratio while smoother layers were obtained at the highest atomic N concentrations. Un-intentionally doped layers were n-type. P-type doping was achieved by doping with Mg.

This book from MRS dedicated to III-Nitrides, focuses on developments in AlN, GaN, InN and their alloys that are now finding application in short-wavelength lasers (~400nm, cw at room temperature) and high-power electronics (2.8W/mm at GHz). Experts from fields including crystal growth, condensed matter theory, source chemistry, device processing and device design come together in the volume to address issues of both scientific and technological relevance. And while much of the book reports on advances in material preparation and the understanding of defect issues, similar advances in material and device processing are also reported. Topics include: growth and doping; substrates and substrate effects; characterization; processing and device performance and design.