复合烧结助剂对Si3N4陶瓷力学性能和热导率的影响

Si₃N₄陶瓷因兼具优异的力学和热学性能, 成为第三代半导体陶瓷基板的首选材料之一。本研究以7种不同离子半径的稀土氧化物(RE₂O₃, RE=Sc、Lu、Yb、Y、Gd、Nd、La)与非氧化物(MgSiN₂)作复合烧结助剂, 通过热压烧结和退火热处理制备了高强、高热导Si₃N₄陶瓷, 并系统研究了复合烧结助剂中RE₂O₃种类对Si₃N₄陶瓷物相组成、微结构、力学性能和热导率的影响规律。热压后Si₃N₄陶瓷力学性能优越, 其中添加Nd₂O₃-MgSiN₂的样品弯曲强度达到(1115±49) MPa。退火处理后Si₃N₄陶瓷的热导率得到大幅提升, 呈现出随稀土离子半径减小而逐渐增大的规律, 其中添加Sc₂O₃-MgSiN₂的样品退火后的热导率从54.7 W·m^-1·K^-1提升至80.7 W·m^-1·K^-1, 提升了47.6%。该结果表明, 相较于国际上通用的Y₂O₃-MgSiN₂和Yb₂O₃-MgSiN₂烧结助剂组合, Sc₂O₃-MgSiN₂有望成为制备高强度、高热导Si₃N₄陶瓷的新型复合助剂。

Mechanical Properties and Thermal Conductivity of Si3N4 Ceramics with Composite Sintering Additives

Si₃N₄ ceramics have become one of the most promising materials for third-generation semiconductor’s ceramic substrates due to its excellent mechanical and thermal properties. In this work, seven rare earth oxides (RE₂O₃, RE=Sc, Lu, Yb, Y, Gd, Nd, La) and non-oxides (MgSiN₂) were used as composite sintering additives to prepare Si₃N₄ ceramics with high strength and high thermal conductivity by hot pressing sintering and annealing. The effects of RE₂O₃ types in the composite additives on the phase composition, microstructure, mechanical properties, and thermal conductivity of Si₃N₄ ceramics were systematically studied. The mechanical properties of Si₃N₄ ceramics after hot pressing sintering were superior to that without hot pressing, and the bending strength of the sample with Nd₂O₃-MgSiN₂ additive reached (1115±49) MPa. After annealing, the thermal conductivity of Si₃N₄ ceramics increased significantly, and gradually increased with the decrease of the rare earth ion’s radius. The thermal conductivity of the sample with Sc₂O₃-MgSiN₂ additive increased from 54.7 W·m^-1·K^-1 to 80.7 W·m^-1·K^-1 (increased by 47.6%) after annealing. The results indicate that Sc₂O₃-MgSiN₂ is expected to be a new composite additive for the preparation of high strength and high thermal conductivity Si₃N₄ ceramics as compared to the internationally accepted combination of Y₂O₃-MgSiN₂ and Yb₂O₃-MgSiN₂ additives.