| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an optical inspection whose inspection accuracy is enhanced by a method wherein a first response and a second response in a first pattern are detected, their results are compared with two responses from corresponding inspection points in a second pattern so as to be processed and a first difference signal and a second difference signal are data-processed together. SOLUTION: In a sensor 16 and a sensor 16', a bright-field signal and a dark-field signal are detected separately, the signals are input separately into a buffer 18 and a buffer 18' and the signals are input further to a defect detector 22 via a delay circuit 20 and a delay circuit 20'. The defect detector 22 performs an operation required to detect the position of a defect on a wafer 14. Then, a highly consistent defect list which combines the bright-field signal with the dark-field signal comprehensively is output. Its data is received by a post processor 24, and whether a captured defect is a pattern defect 44 or a dust particle 46 is determined.</p> |
