Geometrical effects on the charge/discharge properties of quantum dot flash memories

We investigate the addition spectra of arrays of quantum dots (QDs) under different geometrical distributions. We use a Hubbard Hamiltonian where we include intra- and inter-dot interactions. Exact diagonalisation is used to calculate the eigenstates of arrays containing several QDs and the conductance addition spectrum is calculated using the Beenakker Approach for a single-dot generalised to an array of QDs. The charging/discharging process of the QDs is theoretically studied when a bias is applied to a metallic gate on top of the structure. The occupancy and conductance as a function of the gate bias is obtained, a crucial feature to understanding the memory charging process for non-volatile memories that are based on MOS devices with embedded semiconductor QDs. (C) 2004 Elsevier Ltd. All rights reserved.