METHOD AND DEVICE FOR INSPECTING FOREIGN MATTER

• Main Authors: SUGIMOTO ARITOSHI, OOGAYA KAORU, TAGUCHI JUNICHI, IKODA MASAMI, INOUE HIROKO
• Format: Patent
• Language: English
• Published: 30.07.1999
• Edition: 6
• 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

PROBLEM TO BE SOLVED: To improve reliability in foreign matter detection by reducing the occurrence of blooming in foreign matter detection. SOLUTION: A foreign matter inspecting device is formed of a stage 7 to support a semiconductor wafer 1, an optical system 6 with a light source 5 to irradiate the semiconductor wafer 1 with laser light 4, a diffracted light blocking filter 13 in which a blocking film corresponding to a pattern 3 on the semiconductor wafer 1 is formed, a beam splitter 11 to split reflected light 8 from the semiconductor wafer 1 into two, an ND fitter 12 to adjust the amount of light of one of the reflected light 8 after splitting to enter TDI sensors 9, the two TDI sensors 9 to detect two reflected light 8 after splitting, an adding circuit 10 to add the signals of the two reflected light 8 detected by the two TDI sensors 9, and a differential circuit 16 and a comparing circuit 17 to compare the addition signal by the adding circuit 10 with a reference signal registered in advance and to determine that the reflected light 8 is caused by foreign matter 2 in the case that the comparison result exceeds a permissible range.