Analytical Modeling of Source-to-Drain Tunneling in Nanoscale Silicon MOSFET

Sub-10-nm bulk n-MOSFET (metal-oxide -semiconductor field effect transistor) direct source-to- drain tunneling current density using Wentzel- Krammers-Brillouin (WKB) transmission tunneling theory has been simulated. The dependence of the source-to-drain tunneling current on channel length and barrier height is examined. Inversion layer quantization, band-gap narrowing, and drain induced barrier lowering effects have been included in the model. It has been observed that the leakage current density increases severely below 4 nm channel lengths, thus putting a limit to the scaling down of the MOSFETs. The results match closely with the numerical results already reported in literatures.