A scalable model for the substrate resistance in multi-finger RF MOSFETs

We present a method to extract the substrate resistance of RF MOSFETs. We also analyze the substrate networks of multi-finger RF MOSFETs with vertical body contacts and propose a new method to predict the substrate resistance for any number of gate fingers. After the resistance components of the substrate networks are extracted, the effective substrate resistance is expressed as a function of the number of gate fingers. We compare the values of the substrate resistance predicted by the proposed method, and extracted from Y-parameter data. The Y-parameters are obtained from both device simulation and measurement. The model predicts the substrate resistances accurately for multi-finger transistors.