Crystalline Si nano-clusters are successfully produced using pulsed H-2+SiH4 VHF discharges. Their size can be controlled by changing the discharge duration. Si clusters of 1.6 nm in size and 100% crystallinity are produced. Collecting efficiency of them on the substrate decreases by one order of magnitude by heating it from room temperature to 200 degrees C, while their size is around 3 nm irrelevant to its temperature change. (c) 2005 Elsevier B.V. All rights reserved.