Parasitic Gate Capacitance Model for Triple-Gate FinFETs

Triple-gate FinFETs have demonstrated to be promising candidates to push further the performance limits of the microelectronics industry, thanks to their high immunity to short-channel effects. However, owing to their 3-D nature, high parasitic gate capacitances appear that dramatically degrade their high-speed digital and analog/RF performances. Thus, in order to meet the International Technology Roadmap of Semiconductors projection, it is mandatory to find layout or technological solutions to reduce the total parasitic gate capacitance. In this context, it is necessary to develop a model that describes the parasitic capacitance in terms of the FinFET geometry. In this paper, a semianalytical extrinsic gate capacitance model for silicon-on-insulator triple-gate FinFET, based on 3-D numerical simulations, is presented. The model takes into account the external (five components) and internal (two components) fringing capacitances from the gate to the source/drain electrodes as well as the overlap capacitances. Comparisons with experimental results are presented to validate the developed model. Finally, based on the developed model, the evolution of the total parasitic gate capacitance as the channel length is reduced toward the 12-nm technology node is analyzed.