Ultra-wide bandgap β-gallium oxide (Ga2O3) devices are of considerable interest with potential applications in both power electronics and radio frequency devices. However, current Ga2O3 device technologies are limited by the material's low intrinsic electron mobility and thermal conductivity. The former problem can be addressed by employing modulation-doped β-(AlxGa1−x)2O3/Ga2O3 heterostructures in the device architecture. In this work, (AlxGa1−x)2O3/Ga2O3 modulation-doped field effect transistors (MODFETs) have been investigated from a thermal perspective. Thermoreflectance thermal imaging was used to characterize the self-heating of the MODFETs. The (Al0.18Ga0.82)2O3 thermal conductivity (3.1–3.6 W/mK) was determined using a frequency domain thermoreflectance technique. Electro-thermal modeling was used to discern the effect of design parameters such as substrate orientation and channel length on the device self-heating behavior. Various thermal management schemes were evaluated using the electro-thermal device model. From an electro-thermal co-design perspective, the improvement in electrical performance followed by the mitigation of self-heating was also studied. For example, by employing a Ga2O3-on-SiC composite wafer, which was fabricated in this work, a 50% increase in power handling capability can be achieved as compared to a homoepitaxial device. Furthermore, flip-chip heterointegration and double-sided cooling approaches can lead to more than 2× improvement in the power handling capability. Using an augmented double-sided cooling design that includes nanocrystalline diamond passivation, a 5× improvement in the power handling capability can be accomplished, indicating the potential of the technology upon implementation of a suitable thermal management scheme.

中文翻译：

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β-(AlxGa1-x)2O3/Ga2O3调制掺杂场效应晶体管的电热协同设计

超宽带隙 β-氧化镓 (Ga2O3) 器件在电力电子和射频器件中具有潜在的应用价值。然而，当前的 Ga2O3 器件技术受限于该材料的低本征电子迁移率和热导率。前一个问题可以通过在器件架构中采用调制掺杂的 β-(AlxGa1-x)2O3/Ga2O3 异质结构来解决。在这项工作中，从热的角度研究了 (AlxGa1-x)2O3/Ga2O3 调制掺杂场效应晶体管 (MODFET)。热反射热成像用于表征 MODFET 的自加热。(Al0.18Ga0.82)2O3 热导率 (3.1–3.6 W/mK) 使用频域热反射技术确定。电热建模用于辨别设计参数（例如基板方向和通道长度）对器件自热行为的影响。使用电热设备模型评估了各种热管理方案。从电热协同设计的角度来看，还研究了电气性能的改善以及自热的减轻。例如，通过使用在这项工作中制造的 Ga2O3-on-SiC 复合晶片，与同质外延器件相比，功率处理能力可以提高 50%。此外，倒装芯片异质集成和双面冷却方法可以使功率处理能力提高 2 倍以上。采用增强型双面冷却设计，包括纳米晶金刚石钝化，