Electron and hole storage in a floating gate consisting of Si nanocrystals embedded in a SiO2 layer

Abstract

The charge storage in a nano-floating gate consisting of Si nanocrystals (Si-NCs) embedded in a SiO2 layer formed on a Si substrate by using a sonochemical method was investigated. The transmission electron microscopy image and the photoluminescence spectrum showed that Si-NCs were embedded in a SiO2 layer. The capacitance-voltage curves and the electrostatic force microscopy (EFM) images showed that charge storage appeared in the Si-NCs embedded in a SiO2 layer. The EFM images for the Si-NCs embedded in a SiO2 layer under positive and negative voltages showed that electrons and holes were captured in the Si-NCs. The present results indicate that EFM images provide promising evidence for charge storage in Si-NCs embedded in a SiO2 layer.