To analyze defect-assisted elastic tunneling currents through ultrathin SiO2 gate oxides in metal-oxide semiconductor field-effect transistors (MOSFETs), we have combined semiempirical microscopic tight-binding calculations with full-band Monte Carlo transport simulations. Two prototypical devices with channel lengths of 50 and 90 nm were considered. We find that defects having an area density larger than 1011 cm-2 can enhance tunneling currents by several orders of magnitude in both devices. Resonant tunneling effects are predicted to be more pronounced for thicker oxides. For oxides thinner than 2 nm, hot electrons are unlikely to dominate gate leakage currents in the presence of defects.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry