Gate-Drain Distance Optimization in Multi-Layer AlGaN High Electron Mobility Transistors: A Finite Element Analysis

Authors : Yasin Doğan, Osman Çiçek

Pages : 588-603

Doi:10.29132/ijpas.1800457

View : 36 | Download : 144

Publication Date : 2025-12-29

Article Type : Research Paper

Abstract :High Electron Mobility Transistors (HEMTs) based on wide band gap semiconductors and two-dimensional electron gas (2-DEG) channels are crucial for high power and radio frequency applications. Gallium nitride (GaN)-based HEMTs offer superior breakdown voltage, electron transport characteristics, and thermal conductivity for next-generation power electronics. This study investigates the effect of gate-drain distance (Lgd) on electronic characteristics of a multi-layer graded AlₓGa₁₋ₓN HEMT structure (x = 0.05-0.30) on Si substrate using finite element method simulation through SimuApsys modeling software. The Lgd parameter was systematically varied between 0.8 μm and 30 μm to analyze breakdown voltage (Vbr), on-resistance (Ron), current-voltage char-acteristics, and electric field distribution. Simulation results reveal critical trade-offs: short Lgd (3-6 μm) provides low Ron and high current density (Ids,max ≈ 3.95 mA/mm) but lower Vbr (~135V) due to concentrated electric fields, while long Lgd (24-30 μm) achieves high Vbr (~380V) through distributed electric field profiles but with increased Ron and reduced current capacity (~0.65 mA/mm). Application-specific Lgd optimization guidelines are established: 3-6 μm for 350V. This simulation approach enables effective device design optimi-zation without expensive experimental fabrication.
Keywords : SimuApsys, Sonlu Elemanlar Yöntemi, HEMT`ler, Kanal modülasyon etkileri, elektronik parametreler

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