Improved parameter extraction method for GaN HEMT on Si substrate

An improved parasitic elements extraction method applied to GaN on Si devices is presented. Genetic-algorithm based procedure is used to determine a high quality reliable starting values for the extrinsic parameters of proposed small-signal model. Local optimization technique is then used to refine the initial value and find the optimal value for each model element. The validity of the developed method and the proposed small-signal model is verified by comparing simulated small-signal S-parameters with measured ones of a 2-mm (10×200 µm) GaN HEMT-on-Si.