关键词: 大尺寸超薄碳化硅, 室温临时键合, 精密减薄, 先进封装, 散热中介层

Abstract: Driven by rapid progress in artificial intelligence chips and third-generation semiconductor technologies, silicon carbide (SiC) wafers are evolving toward larger sizes, reduced thickness, and improved thickness uniformity. However, SiC thinning remains challenging because of its high hardness (Mohs hardness of approximately 9.2), intrinsic brittleness, sensitivity to grinding-induced damage, and difficulty in maintaining thickness uniformity over large areas. In this work, a large-size ultra-thin SiC wafer fabrication technology based on room-temperature temporary bonding and precision thinning is proposed. The process enables controllable thinning of 6、8 inch SiC wafers to a thickness range of 30-150 μm, with a total thickness variation (TTV) of ≤3 μm and surface roughness (Ra) of ≤2 nm. Characterization of an 8-inch ultra-thin SiC wafer shows a thickness range of 29.5-31.6 μm, a TTV of 2.1 μm, and a surface roughness R_a of 1.61 nm, confirming the feasibility of large-size thinning with high flatness and surface quality. This approach features low stress at room temperature, strong process compatibility, and low-cost scalability, providing a key process route for SiC power-device backside thinning, SiC thermal interposers, and high-density advanced packaging.

Key words: large-size ultra-thin silicon carbide, room-temperature temporary bonding, precision thinning, advanced packaging, thermal interposer