The use of silicon-quantum-dots (Si-QDs) as. oating gates in metal-oxide-semiconductor-field-effect-transistors (MOSFETs) has been attracting great attention. It has been reported that large decreases in drain current are observed within a very short time in Si-QDs memories, indicating that the collective motion of electrons occurs during electron injection into Si-QDs. In this study, we present a theoretical report which indicates that the interaction length between QDs is about 5 -10 nm. From these results, we propose a mechanism for "quantum cascade multi-electron injection''. (C) 2008 Elsevier B. V. All rights reserved.