Microelectronic test structures for rapid automated contactless inline defect inspection

Simple but unique and space-saving microelectronic test structures were designed to afford automated inline contactless defect inspection in a Scanning Electron Microscope (SEM)-voltage contrast (VC) mode for rapid electrical defect-monitoring, along with in situ defect-isolation and characterization capabilities. Such an automated inspection can support accelerated yield learning through increased defect-learning cycles, particularly on the sub-0.25-μm-rule designs, as defects below optical resolution become significant. The system is also capable of the traditional visual inspection in the high-energy secondary-electron emission mode, affording the accurate determination of the “transfer coefficients” between the optical inspection results and the electrical faults from the SEM-VC inspection, needed for any foreign-material or contamination-to-yield model with high correlation or at a high confidence level