METHOD OF INSPECTING A WAFER

• Main Authors: LIM, YOUNG KYU, LEE, KYU, PARK, JE KWON
• Format: Patent
• Language: English
• Published: 21.12.2007
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

A method for inspecting a wafer is provided to remarkably improve precision and rapidity of a defect detecting process by modifying the image information of a defect detecting target in a desired method. A normal signal and a noise signal are set from the image information of a detect detecting target obtained from a wafer(S100). The image information is firstly filtered by filters having different intensities by a first difference value(S200). First ratios of normal signals and noise signals are calculated from the firstly filtered image information(S300). A filter corresponding to a maximum value is selected from the first ratios(S400). With respect to the firstly selected filter, the image information of the defect detecting target is secondly filtered by using filters having different intensities by a second difference value less than the first difference value(S500). Second ratios of normal signals and noise signals are calculated from the secondly filtered image information(S600). A filter corresponding to a maximum value is secondly selected from the first and the second ratios(S700). The image information filtered by using the secondly selected filter is compared with reference image information to determine whether the wafer is defective(S800). Each filter can include an average filter or a Gaussian filter.