Low-temperature modelling of electron-velocity-overshoot effects on 70-250 nm gate-length MOSFETs

Modelling of the increase of MOSFET transconductance produced by electron-velocity overshoot as channel lengths are reduced has been performed at low temperature. The results obtained have been compared to room-temperature ones. To accomplish this, the charge-control model has been used to obtain a simple analytical expression to account for electron-velocity overshoot effects on the performance of very short channel MOSFETs. This model can be easily included in circuit simulators of systems with a huge number of components. Experimental verification of the accuracy of this model is provided. The improvement of MOSFET transconductance due to electron-velocity overshoot is found to be greater at low temperature than at room temperature.