We investigated the thermal characteristics of a recently developed delta-doped $\beta $ -Ga2O3 MESFET using thermoreflectance imaging technique, which enabled temperature measurement with ~250 nm spatial and ~400 ns temporal resolution. We measured the temperature contours on source, drain and gate pads, and estimated peak temperature at different bias conditions, and calculated the thermal time constants of these devices, which can be used to predict their transient thermal behavior. The steady-state temperature is measured to be ~199° C at the gate-center at power =2.56W/mm. A 3-D thermal model combined with a device thermodynamic carrier transport model, which is in good agreement with measurements, was used to predict the temperature profile inside the device. Our analysis establishes that the temperature measured at the gate-center is lower than the overall peak temperature in the device, and the difference between peak and gate-center temperature is higher for the lower gate-voltages at similar power.

中文翻译：

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β-Ga2O3 MESFET 的超快热反射成像和电热建模

我们使用热反射成像技术研究了最近开发的 delta 掺杂 $\beta $ -Ga2O3 MESFET 的热特性，该技术能够以 ~250 nm 的空间分辨率和 ~400 ns 的时间分辨率进行温度测量。我们测量了源极、漏极和栅极焊盘的温度曲线，并估计了不同偏置条件下的峰值温度，并计算了这些器件的热时间常数，可用于预测它们的瞬态热行为。在功率 =2.56W/mm 时，栅极中心的稳态温度测量为 ~199°C。3-D 热模型与器件热力学载流子传输模型相结合，与测量结果非常吻合，用于预测器件内部的温度分布。