Surface morphology control of epitaxial silicon films grown by hot wire chemical vapor deposition using hydrogen dilution

Epitaxial Si films were grown on Si (0 0 1) substrates by hot wire chemical vapor deposition at 600 °C using H2 and Ar-diluted 20% SiH4. The surface morphology and structure were studied by varying the hydrogen dilution of SiH4 during film growth. It was found that the hydrogen dilution affected the surface morphology and surface texture of the epitaxial films. The epitaxial films grown in the hydrogen dilution range of 1.25∼6.25 exhibited the surface texturing with a pyramidal growth front, which increases the surface roughness, and it was confirmed from the microstructural analyses that the pyramidal growth front with the facets of {1 1 1} and {1 1 3} planes was elongated and aligned to one of the 〈1 1 0〉 directions on the epitaxial film surface. Moreover, it was found that the reflectivity of the epitaxial film was influenced by the surface morphology as a function of the hydrogen dilution, which was correlated to the surface texturing and roughness.