A floating gated quantum dot memory using threshold shifting from charges stored in nanoparticles of silicon is expected to be promising candidate for future nonvolatile memory devices. Silicon nanoparticles of 1 $sim$ 5 nm in diameter embedded in SiO$_2$ thin films were made by using an ultrasound induced solution method. SiO$_2$ layers were deposited by RF magnetron sputtering in pure Ar gas. The substrate temperatures was changed from room temperature to 200 $^circ$C under the same deposition conditions. From the capacitance-valtage measurements of metal-oxide-semiconductor capacitors fabricated with the Si nanopaticles in the SiO$_2$ layer, the flat-band voltages changed by about 4.8 V due to charging and discharging to the nanoparticles