Disclosed is apparatus for inspecting a sample. The apparatus includes illumination optics for simultaneously directing a plurality of incident beams at a plurality of azimuth angles towards a sample and collection optics for directing a plurality of field portions of output light from two or more of the plurality of angles towards two or more corresponding sensors. The two or more sensors are arranged for receiving the field portions corresponding to two or more angles and generating two or more corresponding images. The apparatus further comprises a processor for analyzing the two or more images to detect defects on the sample

Accuracy of detecting abnormalities on the surface of a workpiece is improved. An appearance inspection apparatus for inspecting the appearance of a workpiece is provided. The appearance inspection apparatus for inspecting the appearance of the workpiece includes a first lighting unit that irradiates the workpiece with light, a first imaging unit that images the workpiece irradiated by the first lighting unit, a first detection unit that detects a first defect from an image captured by the first imaging unit, a second lighting unit that irradiates the workpiece with light, a second imaging unit that images the workpiece irradiated by the second lighting unit, and a second detection unit that detects a second defect from an image captured by the second imaging unit. The first lighting unit uses coaxial epi-illumination, and the second lighting unit uses coaxial epi-illumination and dome illumination.

Based on job dumps for defects of interest and nuisance events for multiple optical modes, detection algorithms, and attributes, the best combination of the aforementioned is identified. Combinations of each of the modes with each of the detection algorithms can be compared for all the defects of interest detected at an offset of zero. Capture rate versus nuisance rate can be determined for one of the attributes in each of the combinations.

Embodiments of the present disclosure relate to methods for defect inspection. After pattern features are formed in a structure layer, a dummy filling material having dissimilar optical properties from the structure layer is filled in the pattern features. The dissimilar optical properties between materials in the pattern features and the structure layer increase contrast in images captured by an inspection tool, thus increasing the defect capture rate.

A method for inspection of a surface of a sheet moving in a direction, in which the surface is illuminated with first and second light sources, with the first light source emitting light under a first incidence angle range onto a first surface area and the second light source emitting light under a second incidence angle range onto a second surface area of the surface of the sheet. The first and second light sources are operated in pulsed fashion in alternation with a stipulated pulse frequency so that the surface of the sheet is illuminated in alternation with the pulse frequency in the first surface area and the second surface area and the first surface area illuminated by the first light source is observable by an inspector via a mirror in the bright field and the second surface area illuminated by the second light source is observable by the inspector via the mirror in the dark field.

One variation of an optical inspection kit includes: an enclosure defining an imaging volume; an optical sensor adjacent the imaging volume and defining a field of view directed toward the imaging volume; a nest module defining a receptacle configured to locate a surface of interest on a first unit of a first part within the imaging volume at an image plane of the optical sensor; a dark-field lighting module adjacent and perpendicular to the nest module and including a dark-field light source configured to output light across a light plane and a directional light filter configured to pass light output by the dark-field light source normal to the light plane and to reject light output by the dark-field light source substantially nonparallel to the light plane; and a bright-field light source proximal the optical sensor and configured to output light toward the surface of interest.

A system, method, and non-transitory computer readable medium are provided for tuning sensitivities of, and determining a process window for, a modulated wafer. The sensitivities for dies of the modulated wafer are tuned dynamically based on a single set of parameters. Further, the process window is determined for the modulated wafer from prior determined parameter-specific nominal process windows.

Disclosed is apparatus for inspecting a sample. The apparatus includes illumination optics for simultaneously directing a plurality of incident beams at a plurality of azimuth angles towards a sample and collection optics for directing a plurality of field portions of output light from two or more of the plurality of angles towards two or more corresponding sensors. The two or more sensors are arranged for receiving the field portions corresponding to two or more angles and generating two or more corresponding images. The apparatus further comprises a processor for analyzing the two or more images to detect defects on the sample.

The inspection system includes an illumination source, a TDI-CCD sensor, and a dark field/bright field sensor. A polarizer receives the light from the light source. The light from the polarizer is directed at a Wollaston prism, such as through a half wave plate. Use of the TDI-CCD sensor and the dark field/bright field sensor provide high spatial resolution, high defect detection sensitivity and signal-to-noise ratio, and fast inspection speed.

A system, method, and non-transitory computer readable medium are provided for tuning sensitivities of, and determining a process window for, a modulated wafer. The sensitivities for dies of the modulated wafer are tuned dynamically based on a single set of parameters. Further, the process window is determined for the modulated wafer from prior determined parameter-specific nominal process windows.