Device Physics and EM Simulation Based Modeling Methodology for LDMOS RF Power Transistors

In this paper, process, device, and electromagnetic simulations are combined to produce a distributed nonlinear model for an LDMOS RF power transistor. The simulation challenges are handled by using multiple simulators, each with a suitable role in the modeling process. Semiconductor fabrication and device operation are performed through the process and device technology computer aided design (TCAD) tool. The outcome from the TCAD simulations are used to generate a nonlinear compact model for a small section of the device. To form the complete transistor model, many small sections of the compact model are connected by a large-scale interconnect network, which is modeled based on electromagnetic (EM) simulations. For convenient use in circuit simulator, the distributed nonlinear model is implemented by a script-generated comprehensive netlist. It is demonstrated that this purely simulation-based model can accurately predict device behavior under DC, small-signal, and large-signal tests, and is useful for first-pass computer-aided design before wafer fabrication.