Ar+ sputtering of Si wafers surrounded by Mo plates induced the formation of uniform cones over a large area on the Si surface. Scanning electron microscopic study showed that the cones were formed on the entire surface of the Si wafer. The uniform cones were 0.4-0.7 mum in diameter and 5-6 mum high, They were further characterized by means of cross-sectional transmission electron microscopy. and micro-diffraction, It was found that the cone contained a pure Si regime and a Mo-rich regime. In the binary Mo-Si zone, we identified three distinct areas vertically: (1) domains of Mo-induced Si ordered structures (2) a small volume of a new Mo3Si2 structural variant. intergrown with the Si ordered structure: and (3) a small amount of pure Mo nanoparticles covering the surface of the cones. The formation of the large and uniform cones may provide a new surface configuration for potential applications in Surface science and technology. (C) 2002 Published by Elsevier Science B.V.