Enhancing productivity and sensitivity in mask production via a Fast Integrated die-to-database T+R Inspection

摘要

Inspection strategies of transmitted die-to-database pattern inspection (DBT), reflected die-to-database inspection (DBR) and STARlight2~TM (SL2) contamination inspection are employed by mask makers in order to detect pattern defects and contamination defects on photo-masks in process inspection steps and outgoing quality control (OQC). Currently, SL2 inspection is used to detect contamination defects while die-to-database inspections are used to detect pattern defects. However, such inspection strategies need two passes to detect both pattern defects and contamination defects. In this paper we introduce 'Fast Integrated Die-to-Database T+R' (Fast dbTR) and compare its detection capabilities and the productivity to conventional standard detection modes, such as, DBT, DBR and SL2. Programmed reticles and production reticles with pattern defects and contamination defects were used for comparative data collection. During the study, we collected and analyzed inspection data on critical layers such as lines & spaces and contact holes. Empirical data show that 'Fast dbTR' is able to cover the sensitivity required by DBT, DBR and SL2 to detect both pattern defects and contamination defects in one single scan without any loss of productivity in production runs.