Computer Simulation for the Formation of Insulator Layer of Silicon on Insulator by N⁺ and O⁺ Co-implantation

A buried sandwiched layer consisting of silicon dioxide (upper
part), silicon oxynitride (medium part) and silicon nitride (lower part) is formed by N⁺ and O⁺ co-implantation in silicon wafers at a constant temperature of 550°C. The microstructure is performed by cross-sectional transmission electron microscopy. To predict the quality of the buried sandwiched layer, we study the computer simulation for the formation of the SIMON (separation by implantation of oxygen and nitrogen) structure. The simulation programme for SIMOX (separation by implantation of oxygen) is improved in order to be applied in O⁺ and N⁺ co-implantation on the basis of different formation mechanism between SIMOX and SIMNI (separation by implantation of nitrogen) structures. There is a good agreement between experiment and simulation results verifying the theoretical model and presumption in the programme.