Influence of surface steps on N incorporation in GaAsN grown by chemical beam epitaxy

K. Nishimura, H. S. Lee, H. Suzuki, T. Kawahigashi, T. Imai, K. Saito, Y. Ohshita, M. Yamaguchi

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2 Citations (Scopus)


GaAsN epitaxial thin films were grown on GaAs (001) substrate by chemical beam epitaxy (CBE) with dimethylhydrazine ((CH3)2N 2H2, DMHy) as the N source that decomposes at a low temperature. We investigated the influences of the gas flow ratio of DMHy to the group V sources ([DMHy]/V), and surface steps on the N composition in GaAsN thin films. At the growth temperature of 420 °C, the N composition increased with increasing [DMHy]/V, indicating the N composition is determined by the amount of N supplied to the growing surface. In addition, the N composition also increased with increasing surface step density on GaAs (001) substrate orientated towards [010] from 0 to 10°. However, when the density of surface step is low (0-3 × 102 μm-1), the dependence of N composition on surface step density cannot be explained by only the N incorporation at the surface steps on the GaAs substrate. In this case, the surface morphology thought to be rough, since it suggest that N atoms are incorporated at the steps around the nuclei on the growing surface. On the contrary, when the density of surface step is high (3-7 × 102 μm-1), the N incorporation occurs at the steps as they move forward, resulting in the flat surface morphology. It was confirmed by the surface morphology observation of the samples grown on 2 and 10° off substrates, and the root-mean-squares of surface roughness were 1.1 and 0.3nm, respectively. These results indicate the surface morphology of the GaAsN thin films is affected strongly by the step density.

Original languageEnglish
Pages (from-to)2689-2692
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Issue number8
Publication statusPublished - 2006
Externally publishedYes
Event15th International Conference on Ternary and Multinary Compounds, ICTMC-15 - Kyoto, Japan
Duration: 2006 Mar 62006 Mar 10

ASJC Scopus subject areas

  • Condensed Matter Physics


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