Model Order Reduction for Quantum Transport Simulation of Band-To-Band Tunneling Devices

Simulations of nanoelectronic devices with nonequilibrium Green´s function are computationally very intensive, in particular, when combined with multiband approaches, such as the k·p methods. To reduce the cost and make the simulation of realistic devices tractable, we have developed a model order reduction method for the simulation of hole transport in silicon nanowires using three- and six-band k·p models. It is shown in this paper that, with a spurious band elimination process, the method can be readily extended to the eight-band case that enables us to simulate band-to-band tunneling devices. The method is demonstrated via constructing reduced models for indium arsenide (InAs) nanowires and simulation of I-V characteristics of InAs tunneling field-effect transistors (TFETs). The results indicate that significant model reduction can be achieved with good accuracy retained. The method is then applied to study InAs TFETs with different channel orientations and source-pocket TFETs with n-p-i-p doping profiles.