Wafer backside cleaning for defect reduction and litho hot spots mitigation: DI: Defect inspection and reduction

Abstract

With each new advanced technology node, minimum feature sizes continue to shrink. As a result, the devices become denser and exposure tool's depth of focus decreases — making lithography one of the most crucial modules in the process flow. Hence, the elimination of hot spots triggered by problematic pattern regions based on optical simulation, by cleaning wafer backside is a critical issue that needs to be addressed to prevent significant yield degradation.