Growth property of carbon nanotubes onto silicon substrate on which nanotips were formed was examined under an intention to control growth of carbon nanotubes (CNTs). Nanotips were formed onto substrate by reactive ion etching (RIE). The RIE treatment on the surface gave densely formed nanosized tips. After the nanotip formation, CNTs were grown on the substrate by microwave plasma-enhanced chemical-vapor deposition. The growth characteristics of the CNTs depended on size of the nanotips. The results showed that the CNTs grown on the substrate with the nanotip formation give smaller diameter and growth density than those grown without nanotips. (c) 2006 American Vacuum Society.