Small-signal parameter extraction of enhancement-mode MgZnO/ZnO HEMT using advanced optimization algorithms for high-frequency microwave applications
摘要
This study presents a new approach for extracting small-signal parameters in enhancement-mode MgZnO/ZnO high electron mobility transistors (HEMTs), combining a traditional analytical method with advanced optimization algorithms. The extrinsic parameters encompass parasitic capacitances, inductances, and resistances, which are extracted under pinch-off conditions. In contrast, the intrinsic parameters of the small-signal equivalent circuit (SSEC), including gate forward and backward conductance, are determined with precision. Three advanced optimization techniques, quantum genetic algorithm (QGA), covariance matrix adaptation evolution strategy (CMA-ES), and iterative-focusing tree-structured Parzen estimator (IF-TPE), are utilized to minimize the discrepancy between modeled and measured S-parameters. The optimized SSEC models are validated by comparing them with TCAD simulations and existing experimental benchmarks, demonstrating that the QGA-based approach attains the lowest error rate of 1.1%. The MgZnO/ZnO HEMT structure exhibits a threshold voltage of 1.15 V, a maximum extrinsic transconductance of 1520 mS/mm, a saturation current of 1.6 A/mm, a unity-gain cutoff frequency (fT) of 540 GHz, and a maximum oscillation frequency (fmax) of 770 GHz, as demonstrated by DC and RF simulations. The results validate the appropriateness of the proposed device and modeling methodology for high-frequency, high-power microwave, and millimeter-wave applications.