Dissipation of charges in silicon nanocrystals embedded in SiO₂ dielectric films: AN electrostatic force microscopy study

In this paper, we report a mapping of charge transport in silicon nanocrystals (nc-Si) embedded in SiO₂ dielectric films with electrostatic force microscopy (EFM). By using contact EFM mode, positive and negative charges can be deposited on nc-Si. We found that the charge diffusion from the charged nc-Si to the surrounding neighboring uncharged nc-Si is the dominant mechanism during charge decay. A longer decay time was observed for a wider area of stored charge (i.e. 3 charged spots) due to the diffusion of charges being blocked by the surrounding charged nc-Si. This result is consistent with the increase of charge cloud size during the charge decay and the lower charge change percentage for 3 charged spots.