In this work, HfO₂ nanoparticles (np-HfO₂) are embedded within a spin-on glass (SOG)-based oxide matrix and used as a charge trapping layer in metal–oxide–high-k–oxide–silicon (MOHOS)-type memory applications. This charge trapping layer is obtained by a simple sol–gel spin coating method after using different concentrations of np-HfO₂ and low temperature annealing (down to 425 ◦C) in order to obtain charge–retention characteristics with a lower termal budget. The memory’scharge trapping characteristics are quantized by measuring both the flat-band voltage shift of MOHOS capacitors (writing/erasing operations) and their programming retention times after charge injection while correlating all these data to np-HfO₂ concentration and annealing temperature. Since a large memory window has been obtained for our MOHOS memory, the relatively easy injection/annihilation (writing/erasing) of charge injected through the substrate opens the possibility to use this material as an effective charge trapping layer. It is shown that by using lower annealing temperatures for the charge trapping layer, higher densities of injected charge are obtained along with enhanced retention times. In conclusion, by using np-HfO₂ as charge trapping layer in memory devices, moderate programming and retention characteristics have been obtained by this simple and yet low-cost spin-coating method.