Semiconductor

DFinder Inspection

Darkfield systems are based on scattered light collection and are generally used for high-throughput wafer inspection to maintain high production yield and enable early detection of undesirable trends in yield-inhibiting defect counts.

As device geometries shrink and new inspection challenges emerge, specialization in inspection tool capabilities is needed. DFinder is intended primarily for metal interconnect inspection applications at 45nm and below and is the first darkfield inspection tool on the market to use deep ultraviolet (DUV) light. This pioneering system exceeds the capabilities of existing dark field tools in detecting extremely small particle sizes on patterned wafers. It is also specifically designed to inspect back-end-of-line (BEOL) deposition layers, which typically exhibit strong underlayer “noise” that generates high rates of “nuisance” defect readings that have no effect on the properties of the finished device.

DFinder technology uses DUV laser light aimed at the wafer at a low angle of incidence. Two highly sensitive DUV detectors, also positioned at an optimized low angle, collect the light scattered from the wafer surface. Polarization control reduces wafer noise, helping to mask/filter out nuisance defects and deliver accurate data on the defect of interest, with a low false alarm rate. DFinder thus renders inspection of copper and oxide layers deposited at the back end of the semiconductor fabrication cycle (BEOL) more efficient and informative than before, providing manufacturers a closer correlation to their yield.