Resumo

GUARNEROS, C.; ESPINOSA, J. E.; SANCHEZ, V. M.  e  LOPEZ, U.. Study of In_xGa_1-xN layers growth on GaN/Al₂O₃ by MOCVD at different pressures. Superf. vacío [online]. 2013, vol.26, n.3, pp.107-110. ISSN 1665-3521.

We present the In_xGa_1-xN layers growth in a metalorganic chemical vapor deposition (MOCVD) system. First, we growth a GaN epitaxial layer on sapphire substrate, trimethylgallium (TMGa) and ammonia (NH₃) are precursors of gallium and nitrogen, respectively, and hydrogen (H2) is used as the carrier gas. Later, on the GaN epilayer, the growth of the In_xGa_1-xN layer is carried out using trimethylindium (TMIn) as the indium precursor. The In_xGa_1-xN layers were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD pattern shows the diffraction lines which could be ascribed to the formation of hexagonal In₀₁₁₅Ga_0.885N for sample A, and In_0.26Ga_0.74N for sample B, both with the wurtzite type structure. SEM images illustrate the effect of the growth pressure on the films surface morphology. At low pressure the sample A has smaller grain size and higher nuclei density; at high pressure the island size increases and has lower density (sample B). The alloy formation is favored at 550 Torr.

Palavras-chave : In_xGa_1-xN alloys; Growth pressure; XRD patterns; Indium concentration; Vegard's law.