Abstract Amorphous Al2O3 films deposited by atomic layer deposition (ALD) on Ge substrates are a typical gate insulator dielectric used in Ge channel metal-oxide semiconductor field-effect transistor (MOSFET) devices. As Joule heating in the Ge channel alters the MOSFET performance, the thermal transport properties of ALD-Al2O3 films and interfaces between Al2O3 and Ge have become important characteristics. This study measures the thermal transport properties of Al2O3 films on Ge substrates using the thermo-reflectance method. The thermal conductivity кm of the Al2O3 films and the thermal resistivity of the Al2O3/Ge interface were estimated to be 0.83 W m−1 K−1 and 2.8 × 10−8 m2 K W−1, respectively. A significant reduction from the thermal conductivity of crystalline Al2O3 (46 W m−1 K−1) and the large thermal resistivity of the interface were observed. To understand the thermal transport mechanism in the ALD-Al2O3 film, thermal transport was simulated using phonon-based and diffuson theories. It was found that diffuson theory was better at explaining the relatively low thermal conductivity of ALD-Al2O3. The thermal resistivity of the Al2O3/Ge interface was discussed in comparison with that of SiO2/Si interface. The improved understanding of the thermal transport properties of the ALD-Al2O3/Ge stacking structures is essential to obtain the correct prediction of the electrical performance of the MOSFET devices.

中文翻译：

---

原子层沉积制备的锗衬底上氧化铝栅极绝缘膜的热传输特性

摘要 通过原子层沉积 (ALD) 在 Ge 衬底上沉积的非晶 Al2O3 薄膜是典型的栅极绝缘介质，用于 Ge 沟道金属氧化物半导体场效应晶体管 (MOSFET) 器件。由于 Ge 通道中的焦耳热改变了 MOSFET 的性能，ALD-Al2O3 薄膜的热传输特性以及 Al2O3 和 Ge 之间的界面已成为重要的特性。本研究使用热反射法测量 Ge 衬底上 Al2O3 薄膜的热传输特性。Al2O3 薄膜的热导率 кm 和 Al2O3/Ge 界面的热阻估计分别为 0.83 W m-1 K-1 和 2.8 × 10-8 m2 K W-1。观察到结晶 Al2O3 (46 W m-1 K-1) 的热导率显着降低，并且界面的热阻很大。为了理解 ALD-Al2O3 薄膜中的热传输机制，使用基于声子和扩散子的理论模拟了热传输。发现扩散子理论更能解释 ALD-Al2O3 相对较低的热导率。讨论了 Al2O3/Ge 界面的热阻与 SiO2/Si 界面的热阻。更好地理解 ALD-Al2O3/Ge 堆叠结构的热传输特性对于正确预测 MOSFET 器件的电气性能至关重要。使用基于声子和扩散子的理论来模拟热传输。发现扩散子理论更能解释 ALD-Al2O3 相对较低的热导率。讨论了 Al2O3/Ge 界面的热阻与 SiO2/Si 界面的热阻。更好地理解 ALD-Al2O3/Ge 堆叠结构的热传输特性对于正确预测 MOSFET 器件的电气性能至关重要。使用基于声子和扩散子的理论来模拟热传输。发现扩散子理论更能解释 ALD-Al2O3 相对较低的热导率。讨论了 Al2O3/Ge 界面的热阻与 SiO2/Si 界面的热阻。更好地理解 ALD-Al2O3/Ge 堆叠结构的热传输特性对于正确预测 MOSFET 器件的电气性能至关重要。