Large-scale alpha-Si3N4 nanotubes, were synthesized on Si(l 1 1) by hot-wall chemical-vapor-deposition (CVD) with the assistance of Ga2O3. The cylindrical structures were as long as 30 um with the inside diameters ranging between 20 and 60 nm and the outside diameters ranging between 40 and 100 nm. Scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) and high-resolution TEM (HRTEM) were used to characterize the size, composition and the structure of the samples. (C) 2004 Published by Elsevier B.V.