Min So-Ra, Cho Min-Su, Lee Sang-Ho, Park Jin, An Hee-Dae, Kim Geon-Uk, Yoon Young-Jun, Seo Jae-Hwa, Jang Jae-Won, Bae Jin-Hyuk, Lee Sin-Hyung, Kang In-Man
School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea.
Korea Multi-Purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju 38180, Korea.
Materials (Basel). 2022 Jan 21;15(3):819. doi: 10.3390/ma15030819.
The self-heating effects (SHEs) on the electrical characteristics of the GaN MOSFETs with a stacked TiO/SiN dual-layer insulator are investigated by using rigorous TCAD simulations. To accurately analyze them, the GaN MOSFETs with SiN single-layer insulator are conducted to the simulation works together. The stacked TiO/SiN GaN MOSFET has a maximum on-state current of 743.8 mA/mm, which is the improved value due to the larger oxide capacitance of TiO/SiN than that of a SiN single-layer insulator. However, the electrical field and current density increased by the stacked TiO/SiN layers make the device's temperature higher. That results in the degradation of the device's performance. We simulated and analyzed the operation mechanisms of the GaN MOSFETs modulated by the SHEs in view of high-power and high-frequency characteristics. The maximum temperature inside the device was increased to 409.89 K by the SHEs. In this case, the stacked TiO/SiN-based GaN MOSFETs had 25%-lower values for both the maximum on-state current and the maximum transconductance compared with the device where SHEs did not occur; increased from 1.41 mΩ·cm to 2.56 mΩ·cm, and the cut-off frequency was reduced by 26% from 5.45 GHz. Although the performance of the stacked TiO/SiN-based GaN MOSFET is degraded by SHEs, it shows superior electrical performance than GaN MOSFETs with SiN single-layer insulator.
通过严格的TCAD模拟研究了具有堆叠TiO/SiN双层绝缘体的GaN MOSFET的自热效应（SHEs）对其电学特性的影响。为了准确分析这些效应，同时对具有SiN单层绝缘体的GaN MOSFET进行了模拟工作。堆叠TiO/SiN的GaN MOSFET的最大导通电流为743.8 mA/mm，这是由于TiO/SiN的氧化物电容比SiN单层绝缘体的氧化物电容大而得到的改善值。然而，堆叠的TiO/SiN层导致电场和电流密度增加，使器件温度升高。这导致了器件性能的下降。我们从高功率和高频特性的角度模拟并分析了由SHEs调制的GaN MOSFET的工作机制。SHEs使器件内部的最高温度升至409.89 K。在这种情况下，与未发生SHEs的器件相比，基于堆叠TiO/SiN的GaN MOSFET的最大导通电流和最大跨导值均降低了25%；导通电阻从1.41 mΩ·cm增加到2.56 mΩ·cm，截止频率从5.45 GHz降低了26%。尽管基于堆叠TiO/SiN的GaN MOSFET的性能因SHEs而下降，但它仍显示出比具有SiN单层绝缘体的GaN MOSFET更优异的电学性能。
