Quantum effects and single-electron charging effects in nano-scale silicon MOSFETs at room temperature

Two types of extremely small MOSFETs in the 10 nanometer scale have been successfully fabricated and their transport properties are characterized mainly at room temperature. Both quantum confinement effects and single-electron charging effects are clearly observed. In ultra-narrow channel MOSFETs, the increase in threshold voltage owing to the quantum confinement effect is observed, and the mobility enhancement owing to anisotropic electron mass is also discussed. In extremely narrow point-contact MOSFETs, large Coulomb blockade oscillations are observed at room temperature, and two types of negative differential conductance are found at low temperatures. These results strongly suggest that the quantum and single-electron effects should be precisely modeled and incorporated in the design of nano-scale MOSFETs.