Nanocomposite SiO2(Si) films as a medium for non-volatile memory

Abstract

Nanocomposite SiO2(Si) films containing Si nanocrystals (NCs) in a SiO2 dielectric matrix obtained through (i) plasma enhanced chemical vapor deposition (PE CVD) or (ii) pulse laser deposition (PLD) have been investigated as a medium for charge storage. The C–V method was used to characterize charging effects in the MIS structure (capacitor) with a nanocomposite SiO2(Si) film as an insulator. The obtained results indicate (i) the capture of small negative charge at the positive gate voltage in the nanocomposite SiO2(Si) film, (ii) significant capture of positive charge at the negative gate voltage, and that (iii) the difference between the positive and negative charge captured in both cases cannot be explained by dropping a part of the positive gate voltage in the semiconductor’s depletion region. A model of charge transport and capture in nanocrystals of nanocomposite SiO2(Si) film is proposed to explain the experimental results.