| 摘要 |
PURPOSE: To carry out an inspection efficiently by rotating a sample at a fixed angle, detecting the presence/absence of a luminous dot of a reflecting scattering light of a surface of the sample, obtaining a next position to-be-detected for a luminous dot when the luminous dot is detected, detecting the presence/absence of a luminous dot at the position afterwards, and judging whether it is a flaw or an adhering matter from a count of existing steps. CONSTITUTION: A semiconductor wafer 8 is intermittently rotated, e.g. every 9 deg.. A judging process is carried out at every position. At the first, position, image data stored in an image memory 18 are taken into an operating device 19, various treatments are conducted and data of a scattering light on the wafer are extracted. A position of a center of area of every luminous dot of the scattering light is obtained, thereby to calculate and store a reaching position of the wafer 8 after rotated. A luminous dot obtained at the next position is compared with this position. If there is a new luminous dot, a position for the wafer to be shifted is calculated and stored. True above procedure is repeated, for example, up to the 23rd position. When the luminous dots on the wafer 8 are present only at one or two positions, the wafer is judged to have flaws. If the luminous dots are present, over three or more positions, the wafer is judged to have an adhering substance. |
