An analytical extraction method for scalable substrate resistance model in RF MOSFETs

MOSFETs are currently core devices for RF circuit applications. The substrate parameters that significantly affect the small-signal output characteristics are crucial for an accurate RF MOSFET model. The substrate model using single resistance has been proposed, but it deviates from the measured data at frequencies above kink point. Substrate model with pi-type resistance network has been reported, however, it is difficult to predict the network for an arbitrary MOSFET layout because the substrate resistance scales nonlinearly with geometry. The extraction technique for scalable substrate resistance components has been discussed. In this work, we describe an extraction methodology for the scalable substrate resistance components with layout geometry. Moreover, the accuracy of pi-type substrate resistance network for RF MOSFET was also presented under a wide range of frequency.