Metal nanocrystals as catalyst from a metal oxide film were fabricated at various temperatures after hydrogen radical treatment and great quantities of silicon nanowires (SiNWs) were successfully synthesized using the hydrogen microwave afterglow deposition method. Indium (In) metal nanocrystals with size of about 12 nm were obtained from indium oxide film after hydrogen radical pre-treatment for 5 min at 400 degrees C and their quantity reached approximately 3 x 10(10) cm(-2). Subsequently, a numerous SiNWs were grown with the crystal diffraction of (1 1 1), (2 2 0) and (3 1 1). The diameters of the SiNWs mainly ranged from 5 to 120 nm and their lengths extended to about 8.5 mu m. (C) 2008 Elsevier B.V. All rights reserved.