Quantum-mechanical modeling of electron tunneling current from the inversion layer of ultra-thin-oxide nMOSFET's

Quantum-mechanical modeling of electron tunneling current from the quantized inversion layer of ultra-thin-oxide (<40 Å) nMOSFET's is presented, together with experimental verification. An accurate determination of the physical oxide thickness is achieved by fitting experimentally measured capacitance-versus-voltage curves to quantum-mechanically simulated capacitance-versus-voltage results. The lifetimes of quasibound states and the direct tunneling current are calculated using a transverse-resonant method. These results are used to project an oxide scaling limit of 20 Å before the chip standby power becomes excessive due to tunneling currents.