Semiconductor yield has traditionally been limited by random particle-defect based issues. However, as the feature sizes reduced to 0.13 micron and below, systematic mechanism- limited yield loss began to appear as a substantial component in yield loss. In addition, it is becoming clear that ramping yield would take longer and final yields would not reach historical norms. A key factor for not reaching previously attained yield levels is the interaction between design and manufacturing. Yield losses in the newer processes include functional defects, parametric defects and issues with testing. Each of these sources of yield loss needs to analyzed and understood by designers and tool developers. In addition, new techniques and methods must be devised to minimize the impact of these