Improving mean time to develop micro-bump/pillar fabrication process for vertical interconnections by combined defectivity and metrology approach

In this paper, we explored a new process development concept that was recently introduced at CEA/LETI MINATEC campus to minimize the Mean-Time-To-Detection (MTTD) of fabrication problems. This innovative approach aims to speed up the learning curve and reduce its associated cost when developing new innovative technologies. The basic idea is to mix defectivity with metrology by feeding one with the other through a unique hardware/software platform. As a case study, we characterized the fabrication process of a micro-bump and pillar by using information from automatic visual inspection to drive the local metrological investigation. Therefore, the targeted metrology will gain time on root cause findings. Combined results were analyzed automatically, so as to optimize and maintain the related fabrication process.