Our patent, US9157867B2, granted on October 13, 2015, represents a significant innovation in the field of semiconductor inspection using lighting domes equipped with pinhole lenses. This technology addresses key challenges in the inspection of highly reflective surfaces, such as semiconductor wafers, by creating a more efficient lighting and image-capturing system.

Our invention introduces a reflective dome with a small aperture through which a pinhole lens views the object, typically a semiconductor wafer. This small aperture dramatically reduces reflections and unwanted lighting effects that typically interfere with wafer inspection. By using a pinhole lens, we minimize the area of the dome that is obstructed by the viewing aperture, leading to improved image quality and more uniform lighting.

Furthermore, the dome’s reflectance gradient ensures that the light reflected by the dome is distributed evenly over the surface of the wafer. This gradient improves inspection accuracy by reducing hotspots and uneven illumination that can cause false defect detections. The broad-spectrum light source used in our system enhances the clarity of the images by providing a wider range of wavelengths, which is particularly useful in detecting small defects or residues on the wafer’s surface.

One of the key advancements of our patent is the backlighting technique, where light is directed from behind the wafer. This eliminates shadows and improves the uniformity of the light across the wafer, allowing for more precise inspections. The result is a more compact and efficient system that requires a smaller dome and uses less expensive materials while maintaining high inspection standards.

Our patent also covers the ability to inspect wafers using a broad-spectrum integrating camera. This allows for greater sensitivity to subtle variations in the wafer surface, improving the detection of defects and eliminating issues such as the “evil eye” pattern that can occur with narrower light spectrums.

Overall, this patent provides a robust, cost-effective solution to the semiconductor industry, improving inspection processes by ensuring more accurate and uniform lighting, reducing inspection errors, and enhancing image quality.