Abstract:
A system (10) for detecting a level of dirtiness of a filter mat (20) of an airflow cooling system for telecommunications equipment, the system (10) comprising a detector (12) for detecting fluorescent or reflected light backscattered at at least one part (22) of the filter mat (20) comprising or treated with a fluorescent or reflective material, wherein the detector (12) comprises a light source (12a) for illuminating said at least one part (22) of the filter mat (20) with sampling light, and a photosensor (12b) for detecting fluorescent or reflected light backscattered at said at least one part (22) of the filter mat (20) caused by the illumination thereof with sampling light, wherein the system (10) is configured for inferring the level of dirtiness of the filter mat (20) from the amount of detected fluorescent or reflected light.
Abstract:
The present invention discloses methods and a system for scanning scattering contrast inspection for the identification of defects (4) in an actual pattern block (6) on a sample (2) as compared to the desired pattern block on the sample (2) hereby offering a novel solution in order to achieve defect sensitivity and throughput. The method omit the most of the information in reciprocal space (spatial frequency domain) in order to increase the throughput and it captures on the information in the reciprocal space that gives the highest defect information, i.e. contrast signal between the defected and defect-free structure. Subject of the present invention is that the investigation for only deviations from the expected diffraction pattern will allow rapid identification of the defects on the actual pattern of the sample. While the first method describes a method that learns the correct reconstructed diffraction image by the comparison of the repetitive pattern blocks, the second method focusses on the appearance of predictable defects in the spatial frequency domain of the reconstructed diffraction image thereby defining regions of interest where the defects materialize and speeds up the investigations since only those regions of interest have to be considered and compared to the reconstruction diffraction image of a defect-free pattern block.
Abstract:
A product structure (407, 330') is formed with defects (360-366). A spot (S) of EUV radiation which is at least partially coherent is provided on the product structure (604) to capture at least one diffraction pattern (606) formed by the radiation after scattering by the product structure. Reference data (612) describes a nominal product structure. At least one synthetic image (616) of the product structure is calculated from the captured image data. Data from the synthetic image is compared with the reference data to identify defects (660-666) in the product structure. In one embodiment, a plurality of diffraction patterns are obtained using a series overlapping spots (S(l)-S(N)), and the synthetic image is calculated using the diffraction patterns and knowledge of the relative displacement. The EUV radiation may have wavelengths in the range 5 to 50 nm, close to dimensions of the structures of interest.
Abstract:
Disclosed are methods and apparatus for inspecting a photolithographic reticle. An inspection tool is used to obtain a plurality of patch area images of each patch area of each die of a set of identical dies on a reticle. An integrated intensity value for each patch area image is determined. A gain is applied to the integrated intensity value for each patch area image based on a pattern sparseness metric of such patch area image and its relative value to other patch area images' pattern sparseness metric. A difference between the integrated intensity value of each patch of pairs of the dies, which each pair includes a test die and a reference die, is determined to form a difference intensity map of the reticle. The difference intensity map correlates with a feature characteristic variation that depends on feature edges of the reticle.
Abstract:
본 발명은 기판 검사를 위한 기준 데이터 생성방법에 관한 것이다. 상기 방법은 베어 기판을 스캔하여 상기 베어 기판에 대한 영상정보를 획득하는 단계, 상기 영상정보에서 추출한 패드 좌표 정보와 미리 저장되어 있는 설계 정보 상의 패드 좌표 정보를 이용하여 보상 매트릭스를 생성하는 단계, 상기 보상 매트릭스를 상기 영상정보에 적용하여 특징 객체의 좌표 정보를 포함하는 기준 데이터를 생성하는 단계를 포함한다. 상기 방법에 의하면, 기판 검사 시 필요한 캐드 정보를 생성하지 않고 기준 데이터를 신속하게 생성함으로써 작업 효율을 극대화시킬 수 있다.
Abstract:
A reticle that is within specifications is inspected so as to generate a baseline event indicating a location and a size value for each unusual reticle feature. After using the reticle in photolithography, the reticle is inspected so as to generate a current event indicating a location and a size value for each unusual reticle feature. An inspection report of candidate defects and their images is generated so that these candidate defects include a first subset of the current events and their corresponding candidate defect images and exclude a second subset of the current events and their corresponding excluded images. Each of the first included events has a location and size value that fails to match any baseline event's location and size value, and each of the excluded second events has a location and size value that matches a baseline event's location and size value.
Abstract:
With an optical inspection tool, images of a plurality of patches of a plurality of dies of a reticle are obtained. The patch images are obtained so that each patch image is positioned relative to a same reference position within its respective die as another die- equivalent one of the patch images in each the other ones of the dies. For each patch image, an integrated value is determined for an image characteristic of sub-portions of such patch image. For each patch image, a reference value is determined based on the integrated values of the patch image's corresponding die-equivalent patch images. For each patch image, a difference between that patch image's integrated value and an average or median value of its die-equivalent patch images is determined whereby a significant difference indicates a variance in a pattern characteristic of a patch and an average or median pattern characteristic of its die-equivalent patches.
Abstract:
An inspection system is disclosed. An optical assembly establishes an optical path between a light source and a detector. The optical assembly has a relatively large amount of longitudinal chromatic aberration, so that light at a first wavelength focuses on one region of a substrate in the optical path, while light at a second wavelength simultaneously focuses on another region of the substrate. The system can operate in a calibration mode to determine one or more wavelengths of light corresponding to regions of interest in the substrate and in an imaging mode to image regions of interest in the substrate.