Defect inspection system
View Patent ↗A defect inspection system can suppress an effect of light from a rough surface or a circuit pattern and increasing a gain of light from a defect to detect the defect with high sensitivity. When a lens with a large NA value is used, the diameter is 10 a , an angle between the sample surface and a traveling direction of the light from a defect being α 1 . A system receives the light from the defect at a reduced elevation angle α 2 with respect to the sample surface to reduce the scattered light, and to increase the light from the defect. The diameter 10 a is smaller than the diameter 10 b , resulting in a reduction in the ability to focus the scattered light. When a lens having a diameter 10 c is used, the lens interferes with the sample. To avoid the interference, a portion of the lens interfering with the sample is removed.
1. An inspection apparatus comprising:
an illumination system which supplies an object with light, and forms a substantive illuminated line on said object;
a detection system which collects light from said line, wherein:
said detection system includes a plurality of lenses,
said lenses are stacked along an optical axis of said detection system,
said plurality of lenses includes at least an objective lens that is a substantially ellipsoidal lens, and
the inspection apparatus further comprises another detection system which includes a substantially ellipsoidal objective lens, the substantive illuminated line is formed between the detection system and the another detection system when the object is seen from an upper part of the object.
2. The inspection apparatus according to claim 1 , wherein each lens is a substantially ellipsoidal lens.
3. The inspection apparatus according to claim 2 , further comprising an image sensor for detecting the collected light and generating an image.
4. The inspection apparatus according to claim 3 , further comprising a processing system for high speed parallel image processing said image.
5. The inspection apparatus according to claim 4 , wherein said processing system acquires a first image of a first predetermined area on said object and a second image of a second predetermined area adjacent to said first predetermined area, substantially coincides a position of said first image with a position of said second image, and detects an anomaly of said object.
6. The inspection apparatus according claim 5 , further comprising another detection system which includes a substantially ellipsoidal objective lens, the substantive illuminated line is formed between the detection system and the another detection system when the object is seen from an upper part of the object.