Wafer Substrate Bevel Significance to Edge Yield Performance

In the realm of semiconductor technology, the pursuit of higher wafer yield has driven researchers to focus on optimizing wafer edge performance. This paper delves into the relationship between localized four-corner edge yield loss and substrate characteristics, with a specific emphasis on the substrate bevels. In this study, we utilized p-(1 0 0) 200nm wafers sourced from various vendors, with a particular spotlight on a substrate that employs alkaline etching, in contrast to the acid etching used by others. Studies show that after alkaline etching, the (1 0 0) surface exhibits smoother characteristics compared to (1 1 0), posing challenges in particle and film residue adhesion. Furthermore, longer bevels in the specific substrate, resulting in heightened particle adhesion, film wrap-around, and peeling could contribute to defectivity. This intricate interplay between the substrate etching process and bevel length emerges as a significant factor in four-corner edge yield loss investigation. Through experimentation, this study demonstrates an approximate 30% yield improvement in the split lots performed. Overall, this research underscores the paramount importance of reducing defect density at the wafer edge. It sheds light on potential strategies for enhancing wafer yield and product quality in semiconductor manufacturing.