Strain Optimization to Reduce Gate Leakage Current in MOS Transistors with Silicon Oxynitride Gate Dielectrics by Use of First-Principles Calculations

Abstract

We developed a method for optimizing strain to reduce gate leakage current in metal-oxide-semiconductor (MOS) transistors by using first-principles calculations. This method was used to investigate the possibility of decreasing gate leakage current by controlling the strain on gate dielectric materials. We found that compressive strain decreases drastically the leakage current through silicon oxynitride (SiON) gate dielectrics. This change retlects strain-induced change in the band gap of the material. Using finite element analysis to estimate the strain in MOS transistors, we showed the usability of SiON in terms of gate leakage currents and the importance of controlling the strain on the gate dielectric materials.