We report the growth of indium nitride on AlPO4, which is a piezoelectric substrate, by using metal organic vapor phase epitaxy (MOVPE). The substrate we used was the as-grown (011) surface of an AlPO4 crystal grown by hydrothermal synthesis. InN growth occurs as the nonpolar M-plane. The structural, optical, and electrical properties of the epilayer are comparable with those of layers obtained by conventional growth on polar GaN MOVPE templates deposited on C-plane sapphire. We discuss the utilization of other MX-O-4 oxides for growing nitrides.

Thermal annealing of InN layers grown by metal organic vapor phase epitaxy (MOVPE) is investigated in nitrogen atmosphere for temperatures ranging from 400 to 550 degrees C and for heat treatment times up to 12 h. This treatment results in hydrogen outdiffusion, lowering significantly the residual n-type background doping. This mechanism is shown to be reversible through thermal annealing under ammonia atmosphere, responsible of hydrogen incorporation during growth. These results establish a MOVPE process allowing the obtention of InN samples, which exhibit similar electrical properties than molecular beam epitaxy grown samples: a key issue in view of future industrial production of InN based devices.

We report the experimental determination of the interband deformation potentials of indium nitride by combining both optical spectroscopy investigations and high-resolution X-ray measurements performed on a series of InN films grown by metal organic vapour-phase epitaxy. Our approach, which follows the one used for GaN by Shan et al. [Phys. Rev. B. 54 (1996) 13460], gives here for InN a1=-7.66 eV, a2=-2.59 eV, b1=5.06 eV, and b2=-2.53 eV.

We have performed a detailed investigation of the photoluminescence features taken at 2 K on a series of GaxIn1-xN alloys grown by metal-organic vapour-phase epitaxy through the whole composition range. The evolution of the photoluminescence lineshape of GaInN alloys in the indium-rich region is dominated by doping effects rather than by band-gap tailing effects correlated to existence of random chemical crystal inhomogeneities. The lineshape of the photoluminescence indicates a residual electron concentration of about 1018–1019cm-3 in the bulk part of the epilayers. The value we get for the bowing parameter is b=2.8 eV.

We report on the MOCVD growth of InN buffer layers on sapphire substrate for InN growth. The approach used assumes that an optimized InN buffer layer has to exhibit at least the same crystalline quality and sapphire surface coverage than the GaN buffer layers allowing to grow high crystalline quality GaN on sapphire. The buffer layers were characterized by AFM and GID measurements. Sapphire nitridation was investigated: it has a strong influence on in-plane crystalline quality. Two kinds of buffer layers were optimized according to the GaN buffer layer specifications: one of them only presented In droplets at its surface. It was shown that the small amount of In droplets increases the adatoms mobility of the main layer overgrown, leading to a 25% decrease of its in-plane mosaicity, compared to InN films directly grown on sapphire. To achieve a same improvement on InN buffer layer free of In droplets, the InN main layer growth temperature had to be increased from 550 °C. to 600 °C.

We report on the use of dimethylhydrazine (DMHy) and tertiarybuthylhydrazine (TBHy), as alternative nitrogen precursor for GaN low-temperature growth, as well as to improve the InN growth rate. Lowering the GaN growth temperature, would allow growing InN/GaN heterostructures by MOVPE, without damaging the InN layers. Increasing the low InN MOVPE growth rate is of major importance to grow reasonably thick InN layers. In this respect, triethylindium (TEIn) was also used as an alternative to trimethylindium (TMIn). We demonstrate that tertiarybutylhydrazine is a suitable nitrogen source for GaN growth at 600 °C, leading to crystalline GaN layers. These layers exhibited a peak of photoluminescence emission at 3.475 eV, at 2 K, with a narrow linewidth of 18 meV; while no detectable photoluminescence was observed for layers grown with ammonia. This result opens the way to further MOVPE growth of InN and GaN based heterostructures. The unsuccessful GaN growth in a nitrogen or argon ambient using DMHy, in contrast with hydrogen, demonstrates the active role of hydrogen in the growth process. Both DMHy and TBHy were unsuitable to grow InN, but the use of TEIn instead of TMIn together with ammonia resulted at least in doubling the InN growth rate in same growth conditions