Defect inspecting method and apparatus
View Patent ↗A defect inspecting apparatus of the invention solves a problem that in a defect inspecting apparatus, because of improving detection sensitivity of a microscopic defect by reducing a detection pixel size, a focal depth becomes shallow, a height of imaging is varied due to environmental change and the detection sensitivity of a defect becomes unstable. This apparatus comprises an XY stage, which carries a substrate to be inspected and scans in a predetermined direction, and a mechanism having a system of irradiating a defect on the inspected substrate at a slant and detecting the defect by a detection optical system disposed on the upper side, which corrects a height of imaging in real time for change in temperature and barometric pressure in order to keep the imaging in a best condition.
1. A method for detecting a defect of a substrate, the method comprising steps of:
irradiating the substrate with a first light;
detecting a second light from the substrate and forming an image of an illuminated area on the substrate;
measuring an environment of a defect inspecting apparatus, wherein said environment includes a temperature and barometric pressure; and
while inspecting the substrate, changing at least one of a height of a surface of the substrate and a height of a surface of the image based on a table,
wherein said table is used for converting at least one of a deviation from a standard height of a standard substrate surface relative to a change of said environment, and a deviation from a standard height of an image surface relative to change of said environment.
2. The method according to claim 1 , the changing step comprising:
correcting a position of an image sensor involved in forming the image.
3. The method according to claim 1 , the changing step comprising:
changing a height of the substrate.
4. A defect inspecting apparatus comprising:
an illuminating unit which irradiates a substrate with a first light;
a detection unit which detects a second light from the substrate and forms an image of an illuminated area on the substrate;
a plurality of measurement units which measure an environment of the defect inspecting apparatus, wherein said environment includes a temperature and barometric pressure; and
a correcting unit which changes at least one of a height of a surface of the substrate and a height of a surface of the image, wherein:
said correcting unit uses a deviation of said environment, and a plurality of coefficients, and
said coefficients are acquired by at least one of a relationship between said environment and a height of said surface of the substrate, and a relationship between said environment and said image surface.
5. A method for detecting a defect of a substrate, the method comprising steps of:
illuminating the substrate with a first light;
detecting a second light from the substrate;
forming an image of an illuminated area on the substrate;
measuring an environment, wherein said environment includes a temperature and barometric pressure; and
changing at least one of a height of a surface of the substrate and a height of a surface of the image, wherein:
during said changing step, a deviation of said environment and a plurality of coefficients are used, and
said coefficients are acquired by at least one of a relationship between said environment and a height of said surface of the substrate, and a relationship between said environment and said image surface.