The Self Aligned Double Patterning (SADP) module is one scheme to form 3X or 2X line structures by using a dry scanner or immersion scanner. After reliable processes are developed, defect data collection, understanding, characterization, and reduction become important. The learning we obtained at the Mayden Technology Center at Applied Materials reduced ramp time at our customer sites and provided new directions to improve our processes. In this paper, the defect type and evaluation per process to the final 3X or 2X structures in SADP flow are discussed. An in-depth study of the impact of bump defects, bump formation, and a potential solution involving an improved film deposition process are presented.