Defect Inspection Technique Using Surface Plasmon Resonance

Abstract

Inspection using surface plasmon resonance is demonstrated by using a Cr photomask with a 200 nm line and space pattern. This inspection makes it possible to detect Cr defects with a side length of 200 nm connected between lines and hole defects disconnected lines. Our experiments indicate that the smallest size of a detectable defect is estimated to be 6.3 nm and the inspection time is less than 10 min by assuming a multibeam system. Moreover, we can apply surface plasmon resonance to the detection of critical dimension error within 10 nm on the photomask. In conclusion, the resolution and throughput for our inspection technique using surface plasmon resonance are higher than those of a conventional mask inspection technique.