0000000000445123
AUTHOR
M. Mesnier
Structural characterization of original 3D gallium structures grown by LP‐MOCVD
This study is concerned with the growth and characterization of metallic gallium 3D structures, obtained with a single growth step, by the LP-MOCVD technique on various substrates. Commercial organo-metallic is used as gallium precursor and nitrogen as carrier gas. The growth temperature and the reactor pressure are ranking between 500 and 700 °C, and between 150 and 700 torr, respectively. Depending on the elaboration conditions, different 3D structures are obtained such as droplets, cauliflowers, aggregates or thin stems, with micrometer sizes. The morphology, substrate surface density and thermal stability are studied by optical and scanning electron microscopy. At last, X-ray microanaly…
Structure and properties of GaNxOy films grown by nitridation of GaAs (100) substrates
GaAs (100) substrates have been heat-treated in a metal-organic chemical vapor deposition reactor under flows of NH 3 and an oxygen organo-metallic precursor at temperatures between 650°C and 750°C. Yellowish films formed at the surface of all the samples. Gallium, nitrogen and oxygen were detected by EDX analysis of the films. The oxygen content was estimated in the range of at 5-10 at% depending on the heat-treatment temperature. X-ray diffraction and HRTEM results indicate that the structure of the films corresponds to the hexagonal wurtzite phase of GaN with an expanded unit cell. Raman spectra show hands corresponding to the Raman active GaN modes as well as disorder-activated broad ba…