Abstract: New Approaches For Modeling and Design of High-Frequency Devices

Global modeling (electromagnetic-physics-based modeling) of high-frequency devices mandates theintegration of circuit, electromagnetics, and device transport physics into a single package. As circuit operation extends into the millimeter and submillimeter-wave regimes, appropriate device models should be employed for the submicron/nano devices embedded in the circuit.

As the operating frequency (or clock speed) increases in circuits, one must treat signals as electromagnetic waves propagating rather than simple voltages and currents. At sufficiently high frequency, such distributed effects even become problematic within individual devices. At even higher frequencies in the terahertz and far-infrared regime, one has to account for radiation and absorption including the interaction with the whole environment. Further, appropriate device models should be employed as the device size approaches the micro/nano scale. This problem requires development of new and efficient multi-physics simulation (CAD) tools that combine electromagnetic theory, semiconductor transport models, and circuit models into a single package.

In this talk, a review of global modeling of semiconductor devices will be presented. Numerical challenges associated with developing such models will also be discussed. Several applications with different electromagnetic and device physics coupling mechanisms will be provided. This includes modeling of high-frequency PIN switches, modeling of high-frequency multifinger FETs, and finally modeling and design of on-chip THz radiation sources. Efficient techniques for S-parameters and radiation efficiency calculations of complex microwave structures will also be presented.