Memory effect by charging of ultra-small 2-nm laser-synthesized solution processable Si-nanoparticles embedded in Si-Al2O3-SiO2 structure

A memory structure containing ultra-small 2-nm laser-synthesized silicon nanoparticles is demonstrated. The Si-nanoparticles are embedded between an atomic layer deposited high- dielectric Al2O3 layer and a sputtered SiO2 layer. A memory effect due to charging of the Si nanoparticles is observed using high frequency C-V measurements. The shift of the threshold voltage obtained from the hysteresis measurements is around 3.3V at 10/-10V gate voltage sweeping. The analysis of the energy band diagram of the memory structure and the negative shift of the programmed C-V curve indicate that holes are tunneling from p-type Si via Fowler-Nordheim tunneling and are being trapped in the Si nanoparticles. In addition, the structures show good endurance characteristic (>10(5)program/erase cycles) and long retention time (>10 years), which make them promising for applications in non-volatile memory devices.