Yield enhancement and mitigating the Si-chipping and wafer cracking in ultra-thin 20µm-thick 8- and 12-inch LSI wafer

摘要

We have meticulously investigated several pre-grinding parameters such as edge trimming width, depth, and edge-back rinse of smeared glue to mitigate the Si chipping and cracking and to enhance the yield in ultra-thin LSI wafer thinning for the thickness value of up to 20 μm, with respect to different types of temporary bonding glue and the glue thickness. After optimizing several pre-grinding and the post-grinding parameters, we found that an intermediate edge-back-rinse process before the final grinding tremendously reduces the Si chipping and wafer cracking, which enhances the yield of ultra-thin wafer grinding.