Ga2O3 has attracted great attention for electronic device applications due to its ultra-wide bandgap, high breakdown electric field, and large-area affordable substrates grown from the melt. However, its thermal conductivity is significantly lower than that of other wide bandgap semiconductors, which will impact its ability to be used in high power density applications. Thermal management in Ga2O3 electronics will be the key for device reliability, especially for high power and high frequency devices. Similar to the method of cooling GaN-based high electron mobility transistors by integrating it with high thermal conductivity diamond substrates, this work studies the possibility of heterogeneous integration of Ga2O3 with diamond for thermal management of Ga2O3 devices. In this work, Ga2O3 was deposited onto single crystal diamond substrates by ALD and the thermal properties of ALD-Ga2O3 thin films and Ga2O3-diamond interfaces with different interface pretreatments were measured by TDTR. We observed very low thermal conductivity of these Ga2O3 thin films due to the extensive phonon grain boundary scattering resulting from the nanocrystalline nature of the Ga2O3 film. However, the measured thermal boundary conductance (TBC) of the Ga2O3-diamond interfaces are about 10 times larger than that of the Van der Waals bonded Ga2O3 diamond interfaces, which indicates the significant impact of interface bonding on TBC. Furthermore, the TBC of the Ga-rich and O-rich Ga2O3-diamond interfaces are about 20% smaller than that of the clean interface, indicating interface chemistry affects interfacial thermal transport. Overall, this study shows that a high TBC can be obtained from strong interfacial bonds across Ga2O3-diamond interfaces, providing a promising route to improving the heat dissipation from Ga2O3 devices.

中文翻译：

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在金刚石上集成多晶 Ga2O3 用于热管理

Ga2O3 因其超宽带隙、高击穿电场和大面积可负担的从熔体生长的衬底而在电子设备应用中引起了极大的关注。然而，它的热导率明显低于其他宽带隙半导体，这将影响其在高功率密度应用中的使用能力。Ga2O3 电子产品中的热管理将是器件可靠性的关键，尤其是对于高功率和高频器件。与通过将 GaN 基高电子迁移率晶体管与高导热金刚石衬底集成来冷却 GaN 基高电子迁移率晶体管的方法类似，这项工作研究了 Ga2O3 与金刚石异质集成用于 Ga2O3 器件热管理的可能性。在这项工作中，通过ALD将Ga2O3沉积到单晶金刚石衬底上，并通过TDTR测量了不同界面预处理的ALD-Ga2O3薄膜和Ga2O3-金刚石界面的热性能。我们观察到这些 Ga2O3 薄膜的热导率非常低，这是由于 Ga2O3 薄膜的纳米晶体性质导致广泛的声子晶界散射。然而，测得的 Ga2O3-金刚石界面的热边界电导率 (TBC) 比范德华结合的 Ga2O3 金刚石界面大 10 倍左右，这表明界面结合对 TBC 的显着影响。此外，富Ga和富O的Ga2O3-金刚石界面的TBC比清洁界面小约20%，表明界面化学影响界面热传输。全面的，