MOS memory structures by very-low-energy-implanted Si in thin SiO2

The electrical characteristics of thin silicon dioxide layers with embedded Si nanocrystals obtained by low-energy ion beam implantation and subsequent annealing have been investigated through capacitance and current-voltage measurements of MOS capacitors. The effects of the implantation energy (range: 0.65-2 keV), annealing temperature (950-1050 deg. C) and injection oxide characteristics on charge injection and storage are reported. It is shown that the implantation energy allows for a fine control of the memory window characteristics, and various device options are possible including memory operation with charge injection at low gate voltages