Simulation of Phosphorene Field-Effect Transistor at the Scaling Limit

The ultimate scaling limit and device physics of aggressively scaled phosphorene MOSFETs are examined by self-consistent multiscale quantum transport simulations. The MOSFET structure can effectively suppress the ambipolar conduction and decrease the leakage current, and thereby, is more scalable than the Schottky barrier FET structure. The interplay of quantum mechanical effects and highly anisotropic band structure plays a critical role for phosphorene transistors with a sub 10-nm channel length, in which the optimum choice of the transport crystalline direction is completely different from phosphorene FETs with a longer channel length. Even at a sub-10-nm channel length with considerable quantum tunneling effects, the anisotropic band structure still provides a better device performance in terms of ON-current over other 2-D semiconductors with nearly isotropic band structures, such as MoS2. With the optimum choice of the transport direction, both n- and p-type phosphorene FETs meet the International Technology Roadmap for Semiconductor (ITRS) target at the 5-nm technology node.