Memory effect by charging of ultra-small 2-nm laser-synthesized solution processable Si-nanoparticles embedded in Si-Al2 O3 -SiO2 structure

Abstract

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-κ 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 3.3 V at 10/−10 V 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 (>105 program/erase cycles) and long retention time (>10 years), which make them promising for applications in non-volatile memory devices.