<title>Enhanced defect detection capability using combined brightfield/darkfield imaging</title>

Engineering analysis and in-line monitoring common employ either a brightfield TDI imaging or a laser-based darkfield optical approach to defect detection on patterned wafers. Brightfield imaging techniques are commonly used for engineering analysis because of their sensitivity and ability to capture pattern defects, especially in high contrast areas. Laser-based darkfield detection is used because of capture capability on rough deposited layers requiring a good signal to noise ratio. The WF-73X is a laser-based detection system that utilizes a combination of brightfield and darkfield optical configurations. The system offers 0.1 micrometers sensitivity for engineering analysis and 30+ wafer per hour throughput for line monitoring. It combines two propriety technologies employing a five PMT detector configuration.