A scalable eletrothermal model is necessary for a high-power amplifier design for accurate accounting of thermal effects. Toward this end, this study presents a scalable large-signal model of gallium-nitride (GaN) high-electron-mobility transistors (HEMTs) on diamond substrates. First, a three-dimensional (3D) thermal analysis model was established. Then, a modified eletrothemal expression was proposed to predict thermal effects including scalability. For validation, the proposed model was implemented into quasi-physics zone division (QPZD) large-signal model. Results show that the proposed model accurately predicts the I–V curves of devices with different gate widths, gate fingers, and ambient temperatures. Moreover, the results of the model are consistent with on-wafer measurements of 2 × 125, 4 × 125, and 10 × 50 μm of GaN-on-diamond HEMTs, indicating that the proposed model accurately predicts the DC–IV curves, scattering parameters, and large-signal performance. The findings of this study can be useful for designing microwave diamond–GaN HEMT circuits.

中文翻译：

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使用金刚石基 GaN 高电子迁移率晶体管的三维热分析模型的可扩展电热模型

高功率放大器设计需要可扩展的电热模型，以准确计算热效应。为此，本研究提出了金刚石衬底上氮化镓 (GaN) 高电子迁移率晶体管 (HEMT) 的可扩展大信号模型。首先，建立三维（3D）热分析模型。然后，提出了一种改进的 eletrothemal 表达式来预测包括可扩展性在内的热效应。为了验证，将所提出的模型实施到准物理区域划分 (QPZD) 大信号模型中。结果表明，所提出的模型准确地预测了I-V具有不同栅宽、栅指和环境温度的器件曲线。此外，该模型的结果与 2 × 125、4 × 125 和 10 × 50 μm GaN-on-diamond HEMT 的晶圆上测量结果一致，表明该模型准确预测了 DC- IV曲线、散射参数和大信号性能。这项研究的结果可用于设计微波金刚石-GaN HEMT 电路。