METHOD AND APPARATUS FOR INSPECTING DEFECT

• Main Authors: KIKUCHI OSAMU, SAHARA KENJI, SAKAI KAORU
• Format: Patent
• Language: English; Korean
• Published: 18.04.2017
• 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

An objective of the present invention is to separate a defect existing in an inspection target including a fine and multilayered structure such as a semiconductor wafer or an MEMS wafer from a normal pattern and detect a defect with high sensitivity in ultrasonic inspection for the inspection target. To achieve the objective, an inspection target having a pattern formed thereon is photographed to acquire an image of the inspection target. A reference image which does not include a defect is generated from the acquired image of the inspection target. A mask of multiple values is generated to mask non-defective pixels from the acquired image of the inspection target. The brightness of the inspection target image is compared with that of the reference image to calculate defect accuracy. The calculated defect accuracy and the generated mask of multiple values are compared to detect a defect. 본 발명은, 반도체 웨이퍼나 MEMS 웨이퍼 등의 미세하며, 또한 다층 구조를 포함하는 피검사체에 대한 초음파 검사에 있어서, 내부에 존재하는 불량을 정상 패턴과 분리하고, 고감도로 검출 가능하게 하는 것을 과제로 한다. 이러한 과제를 해결하기 위해, 패턴이 형성된 피검사체를 촬상해서 피검사체의 화상을 취득하고, 취득한 피검사체의 화상으로부터 결함을 포함하지 않는 기준 화상을 작성하고, 취득한 피검사체의 화상으로부터 비결함 화소를 마스킹하기 위한 다치의 마스크를 작성하고, 피검사체의 화상과 기준 화상의 밝기를 대조해서 결함 확도를 산출하고, 산출한 결함 확도와 작성한 다치의 마스크를 비교해서 결함을 검출하도록 했다.