Image enhancement technology to get fine defect image for FIB

Abstract

As current feature size on mask is under the wave length of inspection source, it is difficult to distinguish a defect where it is on or from, even though high NA optic lens is used. The disadvantage of this hi-res defect detection method require review step which spend much of inspection time. So this lack of resolution of optical inspection tool requires new review tools such as SEM (Second electron Beam Microscope) or FIB(Focused Ion Beam). As the image of ion beam generally shows speckle noise, we adapted anisotropic nonlinear diffusion technology to remove noise without loss of pattern, by different diffusion along pattern edge. And a fine defect image by image processing to repair was extracted to replace the pattern copy function of FIB.