An accurate model of inversion carrier effective mobility considering scattering mechanisms for nanoscale MOS devices

Electrical characteristics of metal oxide-semiconductor field effect transistor (MOSFET) are numerically studied here. Carriers scattering in the inversion channel of MOSFET dominates the drain current. In this work, carrier scattering in the inversion channel has been measured in terms of mobility. Mobility for ultra-short channel device is far different from the mobility of long channel device. By calculating several important device parameters, such as the threshold voltage, threshold voltage roll-off, sub-threshold swing, the effect of channel length on mobility and drain current, MOSFET with nanoscale channel length is simulated. This outlines an easy approach to model carrier transport in MOS devices using modified semi-classical expressions so that the evaluated results are consistent with that derived quantum mechanically. For this, an existing current-voltage (I-V) compact model is utilized and modified by appending a simplified threshold voltage derivation and a more precise carrier mobility model which is valid for short channel device. As a verification of the proposed model, both the mobility and the drain current are compared with the available experimental and simulated data.