Real Time Fault Site Isolation of Front-End Defects in ULSI-ESRAM Utilizing In-Line Passive Voltage Contrast Inspection

Electrical failures due to front-end defectivity may be detected in-line using large area PVC inspection. Application of this method to a self-aligned contact module of a memory chip is presented. Most of the defectivity affecting this module is non-visual. The PVC inspection results allow representative defects to be cross-sectioned and fully characterized soon after they are created. This approach to FA offers much faster results and much larger sampling of the defectivity affecting each lot than end of line FA. Current experiments to debug the principal defect types are described.