Multi-bias Thermal X-Parameter Model for Efficient Physics-Based FinFET Simulation in RF CAD Tools

In this contribution we present a physics-based multi-bias thermal X-parameter model for a 54 nm Si FinFET transistor. The model is extracted directly in the frequency domain through an in-house developed Technology CAD tool providing Large-Signal analysis using the Harmonic Balance algorithm. Such an approach allows for accurate modeling of parasitic and thermal effects, which are particularly critical in FinFETs, especially in multi-finger devices, due to their peculiar 3D geometry. The X-parameter approach is then exploited to translate the physics-based model into a numerically efficiency parameterized electro-thermal black-box model that can then be adopted for circuit design within EDA tools. Thus, once coupled with an appropriate thermal impedance, it can provide accurate analysis of the device dynamic self-heating. To demonstrate this, we report the analysis of the device, matched at the output for maximum power, at 70 GHz in pulsed mode operation, testing different bias points from class A to class B.