The challenge to record correct fast WLR monitoring data from productive wafers and to set reasonable limits

Fast WLR-Monitoring measurements on productive wafers are strongly time restricted. Essential reliability results must be recorded in seconds. This issue places constraints on the stress method development and also on the assessment of the fast WLR (fWLR) data. In this paper some critical areas of reliability risks covered by fWLR Monitoring are addressed in terms of stress measurement, restricted test structure area, correct raw data screening and the possibility of lifetime/product target quantification. fWLR Monitoring methods can support process qualification and reasonable reliability limits can be a essential part of it. The reliability stress measurements discussed in this work are all employed in high volume production worldwide for various technology families from 0.09μm to 1μm, for logic and memory processes.