A 2-D analytical threshold-voltage model for GeOI/GeON MOSFET with high-k gate dielectric

•A threshold voltage model for GeOI/GeON MOSFET is built in good agreement with the experimental data and other models.•A good trade-off among the MOSFET characteristics can be obtained using the model.•Effects of device parameters on threshold voltage degradation are discussed in detail.

A 2-D analytical threshold-voltage model for ultra-thin-body MOSFET with buried insulator and high-k gate dielectric is established by solving the 2-D Poisson's equation for the gate-dielectric, channel and buried-insulator regions. The validity of the model is confirmed by comparing with experimental data and other models. Using the model, the influences of gate-dielectric permittivity, buried-insulator permittivity, channel thickness, buried-insulator thickness and channel doping concentration on threshold behaviors are investigated. It is found that the threshold behaviors can be improved by using buried insulator with low permittivity, thin channel and high channel doping concentration. However, the threshold performance would be degraded when high-k gate dielectric is used due to enhanced fringing-field effect.