GaN radio frequency (RF) power amplifiers offer many benefits including high power density, reduced device footprint, high operating voltage, and excellent gain and power-added efficiency. Accordingly, these parts are enabling next-generation technologies such as fifth-generation (5G) base transceiver stations and defense/aerospace applications such as high-performance radar and communication systems. However, these benefits can be overshadowed by device overheating that compromises the performance and reliability. In response to this, researchers have focused on GaN-on-diamond integration during the past decade. However, manufacturability, scalability, and long-term reliability remain as critical challenges toward the commercialization of the novel device platform. In this work, a diamond-incorporated flip-chip integration scheme is proposed that takes advantage of existing semiconductor device processing and growth techniques. Using an experimentally validated GaN-on-SiC multifinger device model, the theoretical limit of the cooling effectiveness of the device-level thermal management solution has been evaluated. Simulation results show that by employing a $\sim 2-\mu \text{m}$ diamond passivation overlayer, gold thermal bumps, and a commercial polycrystalline carrier wafer, the power amplifier’s dissipated heat can be effectively routed toward the package, which leads to a junction-to-package thermal resistance lower than GaN-on-diamond high electron mobility transistors (HEMTs). Furthermore, simulation results show that this approach is even more promising for lowering the device thermal resistance of emerging ultra-wide bandgap devices based on $\beta $ -Ga ₂ O ₃ and AlGaN, below that for today’s state-of-the-art GaN-on-diamond HEMTs.

中文翻译：

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Diamond-Incorporated 倒装芯片集成，用于 GaN 和超宽带隙射频功率放大器的热管理

GaN 射频 (RF) 功率放大器具有许多优点，包括高功率密度、减小的器件占用空间、高工作电压以及出色的增益和功率附加效率。因此，这些部件正在支持下一代技术，例如第五代 (5G) 基站收发器和国防/航空航天应用，例如高性能雷达和通信系统。然而，这些好处可能会被设备过热而黯然失色，这会损害性能和可靠性。为此，研究人员在过去十年中一直专注于金刚石基 GaN 集成。然而，可制造性、可扩展性和长期可靠性仍然是新型设备平台商业化的关键挑战。在这项工作中，提出了一种掺入金刚石的倒装芯片集成方案，该方案利用了现有的半导体器件加工和生长技术。使用经过实验验证的 GaN-on-SiC 多指器件模型，评估了器件级热管理解决方案冷却效率的理论极限。仿真结果表明，通过采用 $\sim 2-\mu \text{m}$ 金刚石钝化覆盖层、金热凸块和商用多晶载体晶片，功率放大器的散热可以有效地路由到封装，这导致结到封装的热阻低于金刚石基氮化镓高电子迁移率晶体管（HEMT）。此外，仿真结果表明，这种方法在降低新兴超宽带隙器件的器件热阻方面更有前景。 $\beta $ -Ga ₂ O ₃和 AlGaN，低于当今最先进的金刚石基 GaN HEMT。