Enabling Low-k Liner in Ultra-high Aspect Ratio TSVs by the Timing of Vacuum Treatment in the Vacuum-assisted Spin-coating Technique

作者：Ziyue Zhang, Zhiming Chen, Baoyan Yang, Yigang Hao, Yuwen Su, Yingtao Ding · 年份：2023 · 被引用次数：3 · 研究领域：3D IC and TSV technologies、Copper Interconnects and Reliability、Electronic Packaging and Soldering Technologies

Through-silicon-vias (TSVs) with high aspect ratio and small diameter are highly desired for the miniaturization of high-density 3D heterogeneous integration system. In this paper, the low-cost and low-temperature vacuum-assisted spin-coating technique is deeply investigated to achieve continuous polyimide (PI) liner in ultra-high aspect ratio (>15:1) TSVs, and it is proved that the timing of vacuum treatment is the key enabler for this process. As a result, conformal PI liner is successfully deposited in TSVs with aspect ratio of 18:1 and diameter of 5 μm, and the step coverage is better than 25%. This optimized vacuum-assisted spin-coating technique provides a feasible and convenient solution to the formation of low-k liner in TSVs with ultra-high aspect ratio and small diameter.