基于片内热管理应用的碳化硅深孔刻蚀研究

Deep etching of SiC materials based on chip-level thermal management application

针对传统SiC衬底GaN器件高功率密度工作时的热积累问题,开展基于芯片内部嵌入高热导率材料的GaN器件芯片级热管理技术研究。在实现工艺兼容性的基础上,采用反应离子刻蚀技术对GaN器件有源区下端的SiC衬底进行深孔刻蚀工艺研究,系统地分析了刻蚀气体、射频功率及腔室压强等工艺参数对刻蚀速率的影响,并结合能谱对刻蚀表面的质量和损伤进行分析。实验发现射频功率仅能影响刻蚀速率,而刻蚀气体和压强不仅影响其刻蚀速率,还影响其刻蚀表面质量。最终提出了一种基于反应离子刻蚀技术的SiC深孔刻蚀方法,对器件热管理和SiC深孔刻蚀技术具有重要的指导意义。

Aiming at the problem of heat accumulation of GaN devices on the traditional SiC substrate, high thermal conductivity materials was embedded inside the chip for thermal management of GaN devices. Considering process compatibility, the deep etching process of SiC substrate at the lower end of the active region of GaN device was performed by reactive ion etching, and the effects of process parameters such as the etching gas, RF power, and chamber pressure on the etching rate were analyzed. The quality and damage of the etched surface were analyzed by the energy dispersion spectrum. The results show that the RF power can only affect the etching rate, and the etching gas and pressure affects not only the etching rate, but also the etching surface quality. Finally, the SiC deep etching method based on reactive ion etching was proposed, which could provide guidance for thermal management of the devices and SiC deep etching technology.