Yield improvement in 2x node technology by introducing backside cleaning

Advanced technology nodes require low defects counts at every processing step. Wafer cleaning of the backside is a neglected area. During HVM (high volume manufacturing) for 2x nm nodes we found that cleaning the backside (BS) of the wafer have dramatic improvements in defectivity reduction and yield increase. During HVM of 2x node, defects from BS of wafer were found to fall on the wafer underneath while in the FOUP (Front Opening Unified Pod), specifically in BEOL processing. This contamination fell on the device side/ front side (FS) of the wafer surface and resulted in missing pattern, blocked plating, line voids and surface defects. In this paper, we present the impact of BS cleans on defectivity reduction, and on downstream process resulting in significant yield increase for 2x node HVM.