Tunable memory characteristics of nanostructured, nonvolatile charge trap memory devices based on a binary mixture of metal nanoparticles as a charge trapping layer

The use of a controlled binary mixture of metal nanoparticles was reported for the purpose of tuning the memory characteristics in charge-trap flash memory devices with a comparative and systematic study of the charging/discharging behaviors. All samples were prepared on p-type Si substrates, which were cleaned using an aqueous mixture of H₂SO₄/H₂O ₂, followed by etching with buffered hydrofluoric acid and rinsing with deionized water. HfO₂ tunneling oxide was deposited on the Si substrates using reactive radiofrequency magnetron sputtering, where pure Hf was used as a target. Polystyrene-block-poly(4-vinylpyridine), PS-b-P4VP were added to toluene, a strongly selective solvent for the PS block, and stirred for 2 hours at room temperature, and then cooled down to room temperature. Five clearly distinguishable multiple data levels were obtained under the same programming/erasing bias conditions.