APPARATUS AND METHOD FOR INSPECTING MASK FOR USE IN FABRICATING AN INTEGRATED CIRCUIT DEVICE

摘要

In an embodiment, a mask inspection apparatus for detecting defects in a semiconductor pattern on a mask includes optics for combining light transmitted through or reflected from the mask with a reference beam. The two light beams are transmitted through a second-order non-linear optical system. Mask defects affect the transmitted/reflected light and may be detected by analyzing the transmitted light intensity. The second-order non-linear optical system amplifies selected elements of the combined beam, thus improving detection.