Effect of variation of topological changes on the Equivalent Circuit Parameters of pseudomorphic HEMTs

This paper describes the study of effect of variation of topological changes on parameters of pseudomorphic HEMTs. Devices with 2 gate fingers, having gate width of 150 µm, source-drain spacing of 4 µm and 3 µm, and with two different gate structures, viz., π and T types were fabricated. On-wafer measurement of S-parameters for different devices was done from 100 MHz to 40 GHz under different bias conditions. Using this data, all the Equivalent Circuit Parameters (ECPs) were then extracted for each device. This method was then used for the calculation of the ECPs of 4 µm and 3 µm spacings, and trends of various parameters were analyzed.