Two pairs of alignment targets (one aligned, one misaligned by a bias distance) are formed on different masks to produce a first pair of conjugated interference patterns. Other pairs of alignment targets are also formed on the masks to produce a second pair of conjugated interference patterns that are inverted the first. Misalignment of the dark and light regions of first interference patterns and the second interference patterns in both pairs of conjugated interference patterns is determined when patterns formed using the masks are overlaid. A magnification factor (of the interference pattern misalignment to the target misalignment) is calculated as a ratio of the difference of misalignment of the relatively dark and relatively light regions in the pairs of interference patterns, over twice the bias distance. The interference pattern misalignment is divided by the magnification factor to produce a self-referenced and self-calibrated target misalignment amount, which is then output.

An apparatus for and method of sensing alignment marks in which a self-referencing interferometer based sensor outputs standing images of the alignment marks and camera device is used to capture the images as output by the sensor and a detector is used to obtain phase information about the alignment marks from the images as output by the sensor.

A self-referencing interferometer (SRI) system for an alignment sensor apparatus includes a first prism and a second prism. The first prism has an input surface for an incident beam. The second prism is coupled to the first prism and has an output surface for a recombined beam. The recombined beam includes a first image and a second image rotated by 180 degrees with respect to the first image. The first and second prisms are identical in shape. A dual self-referencing interferometer (DSRI) system for an alignment sensor apparatus includes a first prism assembly having an input surface for a first incident beam and a second incident beam, and a second prism assembly coupled to the first prism assembly and having an output surface for a first recombined beam and a second recombined beam. The first and second prism assemblies are identical in shape.

A sensor apparatus (300) for determining a position of a target (330) of a substrate (W) comprising, projection optics (315;321) configured to project a radiation beam (310) onto the substrate, collection optics (321) configured to collect measurement radiation (325) that has scattered from the target, a wavefront sensing system (335) configured to determine a pupil function variation of at least a portion (355) of the measurement radiation and output a signal (340) indicative thereof, and a measurement system (350) configured to receive the signal and to determine the position of the target in at least partial dependence on the collected measurement radiation and the determined pupil function variation of at least a portion of the measurement radiation.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a semiconductor device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a substrate, a first device layer disposed on the substrate, and a first bonding layer disposed above the first device layer and including a first bonding contact and a first bonding alignment mark. The second semiconductor structure includes a second device layer, and a second bonding layer disposed below the second device layer and including a second bonding contact and a second bonding alignment mark. The first bonding alignment mark is aligned with the second bonding alignment mark at the bonding interface, such that the first bonding contact is aligned with the second bonding contact at the bonding interface.

Provided is a lithography apparatus capable of detecting the abnormal holding of an original in a shorter period of time. The lithography apparatus is configured to form a pattern on a substrate through use of the original, and includes: a holding unit configured to hold the original on which a first mark is formed; a measuring unit configured to pick up an image of the first mark; and a control unit configured to: cause the measuring unit to obtain the image of the first mark on the original held by the holding unit with a focus position of the measuring unit being adjusted to a reference position; and determine that the original is being abnormally held by the holding unit when a change in a first contrast, which is a contrast of the image of the first mark with respect to a reference contrast, falls out of an allowable range.

According to one embodiment, a position measuring apparatus includes a substrate holding part, a projection part, a liquid supply part, an imaging part, a position measuring part, and a control unit. The substrate holding part is configured to hold a substrate including at least part of a circuit pattern. The projection part is configured to irradiate the substrate held on the substrate holding part with illumination light, and to transmit reflected light from the substrate, of the illumination light radiated on the substrate. The liquid supply part is configured to supply a liquid into a space between the substrate held on the substrate holding part and the projection part. The imaging part is configured to receive the reflected light transmitted through the projection part, and to generate an image signal based on the reflected light. The position measuring part is configured to obtain positional information on a position of the substrate holding part. The control unit is configured to determine a coordinate position of the at least part of a circuit pattern in the substrate, on a basis of the positional information and the image signal.

A method of applying a measurement correction includes determining an orthogonal subspace used to characterize the measurement as a plot of data. A first axis of the orthogonal subspace corresponds to constructive interference output from an interferometer of the metrology system plus a first error variable and a second axis of the orthogonal subspace corresponds to destructive interference output from the interferometer of the metrology system plus a second error variable. The method also includes determining a slope of the plot of data and determining a fitted line to the plot of data in the orthogonal subspace based on the slope.

A compensator for manipulating a radiation beam traveling along an optical path. The compensator includes a fixed support holding a first optical wedge and an adjustable support holding a second optical wedge. The adjustable support includes a base, a stage holding the second optical wedge, first and second flexures, and a drive block. The stage defines a cavity and is movable relative to the base and the fixed support. The first and second flexures couple the stage to the base such that the stage translates along a stage path. The drive block is disposed in the cavity of the stage and is configured to translate along a drive block path perpendicular to the optical path and perpendicular to the stage path. The drive block includes first and second drive bearing surfaces configured to translate the stage in first and second stage directions, respectively, along the stage path.

An alignment mark for determining a two-dimensional alignment position of a substrate is discussed. The alignment mark includes an array of patterns. The array of patterns includes a first set of patterns and a second set of patterns arranged. The first set of patterns is arranged in a first sequence along a first direction. The second set of patterns is arranged in a second sequence along the first direction. The second sequence is different from the first sequence. Each pattern of the array of patterns is different from other patterns of the array of patterns that are adjacent to the each pattern.