This paper reports on TCAD simulation of beta-gallium oxide (β-Ga₂O₃) MOSFET with the channel recessed into a 1-µm thick Si-doped (1 × 10¹⁸ cm⁻³) epitaxial layer. We optimized gate recess thickness to achieve both depletion mode (D-mode) and enhancement mode (E-mode) operations. The simulated β-Ga₂O₃ MOSFET structures show optimum D-mode and E-mode characteristics for 150-nm and 15-nm active channel thicknesses, respectively. A comparative study is also done to analyze the thermal and electrical effects by simulating the heteroepitaxial β-Ga₂O₃ layer on sapphire substrate [201] and homoepitaxial β-Ga₂O₃ layer on β-Ga₂O₃ [010] substrate. The MOSFET devices based on the β-Ga₂O₃ layers on sapphire substrates show improved performance compared to the devices based on the β-Ga₂O₃ layers on β-Ga₂O₃ substrates in terms of drain current, transconductance, and breakdown voltage. β-Ga₂O₃ epitaxial layers on sapphire substrates exhibit a drain current density of 425 mA/mm with a peak transconductance of 12.2 mS/mm for D-mode operation and 153 mA/mm drain current density with a peak transconductance of 20.8 mS/mm for E-mode operation. In contrast, the MOSFET devices based on the β-Ga₂O₃ epitaxial layers on β-Ga₂O₃ substrates show a drain current density of 415 mA/mm for D-mode operation and 144 mA/mm drain current density with 3.2 mS/mm peak transconductance for E-mode operation. The MOSFET devices based on the β-Ga₂O₃ epitaxial structures on sapphire and β-Ga₂O₃ substrates show reliable switching properties with improved subthreshold slope and high I_on/I_off ratio of 10¹¹. These simulation results show potential of laterally scaled β-Ga₂O₃ MOSFETs for power-switching applications.

本文报告了 β- 氧化镓 (β-Ga ₂ O ₃ ) MOSFET 的 TCAD 模拟，其中沟道凹入 1 µm 厚的硅掺杂 (1 × 10 ¹⁸ cm ^-3 ) 外延层中。我们优化了栅极凹槽厚度以实现耗尽模式（D 模式）和增强模式（E 模式）操作。模拟的 β-Ga ₂ O ₃ MOSFET 结构分别针对 150 nm 和 15 nm 有源沟道厚度显示最佳 D 模式和 E 模式特性。通过模拟蓝宝石衬底上的异质外延 β-Ga ₂ O _{3层 [201] 和同质外延 β-Ga 2} O层，还进行了比较研究以分析热效应和电效应₃层在β-Ga ₂ O ₃ [010]衬底上。_{与基于β-Ga 2} O _{3衬底上的β-Ga 2} O ₃层的器件相比，基于蓝宝石衬底上的β-Ga ₂ O ₃层的MOSFET器件在漏极电流、跨导和击穿电压。β-Ga ₂ O ₃蓝宝石衬底上的外延层在 D 模式下表现出 425 mA/mm 的漏极电流密度和 12.2 mS/mm 的峰值跨导，在 E 模式下表现出 153 mA/mm 的漏极电流密度和 20.8 mS/mm 的峰值跨导手术。相比之下，基于 β-Ga 2 O 3 衬底上的 β-Ga 2 O 3 外延层的 MOSFET 器件_显示D_模式操作的_漏极电流密度为 415 mA/mm 和 3.2 的 144 mA/mm 漏极电流密度E 模式操作的 mS/mm 峰值跨导。基于β-Ga _{2 O 3 蓝宝石和β-Ga 2} O _3外延结构_的MOSFET器件基板显示出可靠的开关特性，具有改进的亚阈值斜率和10 ^{11的高 I} _on /I _off比率。这些仿真结果显示了横向缩放的 β-Ga ₂ O ₃ MOSFET 在功率开关应用中的潜力。