Size Dependent Influence of the PAD and Gate Parasitic Elements to the Microwave and Noise Performance of the 0.35 μm n and p Type MOSFETS

Noise and s-parameters of the p and n type MOSFETs were measured and simulated for the different bias points. The pad parasitic models of the "short" and "open" were extracted by means of comparison of measured and simulated sparameters. The influence of the pad elements on the microwave noise was analyzed. The simulation of intrinsic device noise was performed on the basis of good fit of measured and simulated noise and s-parameters of the DUT. For the narrow gate (50μm) width devices the pad parasitics significantly affect microwave noise performance for both p and n type devices. At the lower drain currents the kinks and loops in the s-parameters were observed. At low drain current a resonant peak in NF_min and R_n around 8 GHz was found. Those resonant effects observed in noise and s-parameters diminish with the increase of the drain current and were qualitatively accounted for by the simulations by using equivalent circuit with the parasitic inductive element coupled to the gate.