Extraction of T-type substrate resistance components for radio-frequency metal-oxide-semiconductor field-effect transistors based on two-port s-parameter measurement

In this paper, we present an analytical parameter extraction method for the T-type substrate network (substrate resistance components) of RF metal-oxide-semiconductor field-effect transistors (MOSFETs) based on simple two-port S-parameter measurements. To improve the accuracy of the parameter extraction, the electrode resistance components of the gate, source, and drain regions are used in the equivalent circuit model of RF MOSFETs in the off-state. The values of the substrate resistance components are extracted directly from the two-port S-parameter measurement data and not from the existing complex three- or four-port measurement, and their scalability according to device geometry is excellent. Using the proposed small-signal circuit and extracted parameters, it is verified that the output admittances of MOSFETs are successfully modeled up to 40 GHz. The verification was performed by a comparison of simulated and measurement data for 130-nm-technologynode complementary metal-oxide-semiconductor (CMOS) devices.