Impact of quantum mechanical tunneling on off-leakage current in double-gate MOSFET using a quantum drift-diffusion model

With the growing use of wireless electronic systems, off-state leakage current in MOSFETs appears as one of the major physical limitations. Measurements of quantum tunnel current between source-drain (S-D) have recently shown that it will become detrim(1) ental in bulk MOSFET architecture for channel lengths around 5nm and at low temperature (less than or equal to100K) [1]. In this paper we investigate, using a 2D quantum drift-diffusion model, the influence of source-to-drain tunneling on off-state-leakage current in double-gate MOSFETs. It is shown that in double-gate MOSFET architecture (contrary to bulk architecture) quantum tunnel current component will be a non negligible part of the off-state leakage current for ultra-thin film thicknesses, even at room temperature.