An overlay pattern includes a light-transmitting region and a first light-proof region. The first light-proof region and the light-transmitting region are arranged on a same plane, and an area of the first light-proof region is larger than an area of the light-transmitting region. An orthographic projection of the first light-proof region on the plane and an orthographic projection of the light-transmitting region on the plane do not overlap and form a first rectangular region.

The present disclosure relates to a semiconductor mark and a forming method thereof. The semiconductor mark comprises: a previous layer mark comprising first patterns and at least one second pattern, the second pattern being located between adjacent first patterns, the first pattern being different from the second pattern in material property. Since the first pattern and the second pattern in the previous layer mark in the semiconductor mark according to the present disclosure are different in material property, during measurement, the first pattern and the second pattern are different in reflectivity for measurement light. Thus, the contrast of images of the first pattern and the second pattern obtained during measurement is improved, the positions and boundaries of the first pattern and the second pattern are clearly determined, and the measurement of the previous layer mark is more accurate.

A device includes a diffraction-based overlay (DBO) mark having an upper-layer pattern disposed over a lower-layer pattern, and having smallest dimension greater than about 5 micrometers. The device further includes a calibration mark having an upper-layer pattern disposed over a lower-layer pattern, positioned substantially at a center of the DBO mark, and having smallest dimension less than about 1/5 the size of the smallest dimension of the DBO mark.

A method of processing a wafer is provided. The method includes providing a reference plate below the wafer. The reference plate includes a reference pattern. The reference plate is imaged to capture an image of the reference pattern by directing light through the wafer. A first pattern is aligned using the image of the reference pattern. The first pattern is applied to a working surface of the wafer based on the aligning.

The present application provides a method for avoiding a damage to an overlay metrology mark, forming a plurality of raised silicon structures on an active area of a scribe line area on a silicon substrate, forming first to third dielectric layers on the silicon structure, and forming an axial structure of a fin and a spacer on the first to third dielectric layers; forming a shallow trench isolation (STI) area on the silicon substrate between the axial structures; removing a portion of the silicon structure along the height thereof on the scribe line area, the height of the residual silicon structure is 150-300 angstroms higher than that of the STI area; forming a plurality of dummy gates on the residual silicon structure on the scribe line, then applying a dielectric layer to fill a gap between the dummy gates, polishing the dielectric layer to expose the top of the dummy gate.

A product includes a semiconductor substrate, with at least first and second thin-film layers disposed on the substrate and patterned to define a matrix of dies, which are separated by scribe lines and contain active areas circumscribed by the scribe lines. A plurality of overlay targets are formed in the first and second thin-film layers within each of the active areas, each overlay target having dimensions no greater than 10 μm×10 μm in a plane parallel to the substrate. The plurality of overlay targets include a first linear grating formed in the first thin-film layer and having a first grating vector, and a second linear grating formed in the second thin-film layer, in proximity to the first linear grating, and having a second grating vector parallel to the first grating vector.

A radiation system comprising a radiation source and a radiation conditioning apparatus, wherein the radiation source is configured to provide a radiation beam with wavelengths which extend from ultraviolet to infrared, and wherein the radiation conditioning apparatus is configured to separate the radiation beam into at least two beam portions and is further configured to condition the at least two beam portions differently.

A method of characterizing asymmetric depositions on a target is provided. The method includes forming at least four asymmetrical petals in a layer on a substrate, and depositing a light-absorbing material on the at least four asymmetrical petals, wherein the light-absorbing material deposits unevenly on a plurality of walls of the at least four asymmetrical petals. The method further includes determining a pattern shift response (PSR) from the light-absorbing material on each of the walls of the at least four asymmetrical petals, and converting the pattern shift response (PSR) to an asymmetry of thicknesses of the light-absorbing material deposited on facing walls of the at least four asymmetrical petals. The method further includes correcting an overlay petal position based on the asymmetry of thicknesses.

A radiation source arrangement causes interaction between pump radiation (340) and a gaseous medium (406) to generate EUV or soft x-ray radiation by higher harmonic generation (HHG). The operating condition of the radiation source arrangement is monitored by detecting (420/430) third radiation (422) resulting from an interaction between condition sensing radiation and the medium. The condition sensing radiation (740) may be the same as the first radiation or it may be separately applied. The third radiation may be for example a portion of the condition sensing radiation that is reflected or scattered by a vacuum-gas boundary, or it may be lower harmonics of the HHG process, or fluorescence, or scattered. The sensor may include one or more image detectors so that spatial distribution of intensity and/or the angular distribution of the third radiation may be analyzed. Feedback control based on the determined operating condition stabilizes operation of the HHG source.

A metrology system may include a controller to receive a first metrology dataset associated with a first set of metrology target features on a sample including first features from a first exposure field on a first sample layer and second features from a second exposure field on a second sample layer, where the second exposure field partially overlaps the first exposure field. The controller may further receive a second metrology dataset associated with a second set of metrology target features including third features from a third exposure field on the second layer that overlaps the first exposure field and fourth features formed from a fourth exposure field on the first layer of the sample that overlaps the second exposure field. The controller may further determine fabrication errors based on the first and second metrology datasets and generate correctables to adjust a lithography tool based on the fabrication errors.