The benefits of dry oxidation of n ‐GaN for the fabrication of metal‐oxide‐semiconductor structures are reported. GaN thin films grown on sapphire by MOCVD were thermally oxidized for 30, 45 and 60 minutes in a pure oxygen atmosphere at 850 °C to produce thin, smooth GaOx layers. The GaN sample oxidized for 30 minutes had the best properties. Its surface roughness (0.595 nm) as measured by atomic force microscopy (AFM) was the lowest. Capacitance‐voltage measurements showed it had the best saturation in accumulation region and the sharpest transition from accumulation to depletion regions. Under gate voltage sweep, capacitance‐voltage hysteresis was completely absent. The interface trap density was minimum (Dit = 2.75×1010 cm–2eV–1) for sample oxidized for 30 mins. These results demonstrate a high quality GaOx layer is beneficial for GaN MOSFETs. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Aluminum nitride (AlN) was grown on c‐plane sapphire substrates by hydride vapor phase epitaxy (HVPE). The experiments utilized a two zone inductively heated hot‐wall reactor capable of temperatures exceeding 1500 °C. The precursors of aluminum monochloride (AlCl) and aluminum trichloride (AlCl3) were used, and it was determined that AlCl3 was more thermodynamically conducive to single crystalline AlN growth at 1450 °C. AlN templates were optimized at a thickness of 1 µm without cracking. The double axis X‐ray diffraction (XRD) rocking curves full width half maximums (FWHMs) were reproducibly demonstrated with an average of 130 arcsec for the (002) and 516 arcsec for the (102). The AlN was transparent in the UV spectrum with a band gap cut off of 200 nm. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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The present study was undertaken to determine if boron phosphide (BP) crystals could be produced by a simple technique, close-spaced vapor transport (CVST). This technique has proven very successful in achieving very high growth rates for a wide variety of materials including ZnSe, AlN, and SiC. Both silicon (100) and sapphire substrates were used for the CSVT growth. The resulting films were characterized by Raman spectroscopy. Sublimation of BP powder from 1050 to 1450 °C in an argon atmosphere produced a range of deep orange colour, single and polycrystalline BP crystals. The crystal size increased and the crystal density decreased with increasing temperature. Well-faceted crystals were produced at an intermediate temperature of 1200 °C. At temperatures higher then 1450 °C no BP crystals were grown. Only a fibrous mass of fine whiskers, loosely attached to the substrate were produced. The peak position of the Raman LO mode of the BP crystals was shifted to higher wavenumbers than the BP powder source, suggesting that the crystals were compressively strained.