Self-organized formation of Si nanodot arrays on the oxidized Si(1 0 0) surfaces has been studied using scanning tunneling microscopy. The growth of the oxide layer and subsequent Si deposition have been conducted under ultra-high vacuum conditions. Number density of the grown Si nanodots was in the range from 3 x 10(12) to 8 x 10(12) cm(-2) and their average size varied from 3 to 5 nm. Effect of the SiO2 layer thickness (0.2-2.2 nm), amount of deposited Si (0.5-7.5 ML) and growth temperature (60-450 degrees C) on the Si nanodot number density and size distribution has been determined. (c) 2004 Elsevier B.V. All rights reserved.