A method for generating an alignment signal that includes detecting local dimensional distortions of an alignment mark and generating the alignment signal based on the alignment mark. The alignment signal is weighted based on the local dimensional distortions of the alignment mark. Detecting the local dimensional distortions can include irradiating the alignment mark with radiation, the alignment mark including a geometric feature, and detecting one or more phase and/or amplitude shifts in reflected radiation from the geometric feature. The one or more phase and/or amplitude shifts correspond to the local dimensional distortions of the geometric feature. A parameter of the radiation, an alignment inspection location within the geometric feature, an alignment inspection location on a layer of a structure, and/or a radiation beam trajectory across the geometric feature may be determined based on the one or more detected phase and/or amplitude shifts.

An alignment method and an alignment system are provided. The alignment method includes: providing a wafer including an exposed surface, wherein an alignment mark and a reference point with a reference distance are provided on the exposed surface; placing the wafer on a reference plane; performing an alignment measurement on the exposed surface to obtain a projection distance, configured as a measurement distance, between the alignment mark and the reference point on the reference plane; performing a levelling measurement between the exposed surface and the reference plane to obtain levelling data of the exposed surface; obtaining a distance, configured as an expansion reference value, between the alignment mark and the reference point in the exposed surface; obtaining an expansion compensation value based on a difference between the expansion reference value and the reference distance; and adjusting parameters of a photolithography process based on the expansion compensation value for an alignment.

A method of determining a position of a product feature on a substrate, the method includes: obtaining a plurality of position measurements of one or more product features on a substrate, wherein the measurements are referenced to either a positioning system used in displacing the substrate in between measurements or a plane parallel to the surface of the substrate; and determining a distortion component of the substrate based on the position measurements.

A movable table system comprising two identical tables on a common rail arrangement having a linear rail region underneath a detection unit and a processing unit, and therefore the tables can be alternatingly moved in a straight line along the common rail arrangement, in the same table-movement direction, fully underneath the detection unit and processing unit, and can be independently controlled by a computer unit. The movable table system provides a new option for processing planar workpieces, in which a particularly high throughput rate and improved precision can be achieved using merely one processing unit.

A measurement device for measuring a relative position between alignment marks includes an illumination unit capable of illuminating the alignment marks at a plurality of wavelengths, a detection unit that detects light from the alignment marks, a processing unit that obtain the relative position between the alignment marks, and an adjustment unit that adjusts a relative amount between light amounts of the plurality of wavelengths so that a relative value between detection light amounts of light from the alignment marks falls within a predetermined range.

A detecting apparatus that detects a mark includes: an imaging device configured to perform imaging of the mark; and a controller configured to control the imaging device. The controller is configured to control the imaging device such that only a period in which a position of an object with the mark is within a tolerance is a period of the imaging before the position converges within the tolerance.

An alignment system includes: a light emitting device located on one side of an object to be aligned for emitting light towards the object to be aligned; a light receiving device located on the other side of the object to be aligned and at a standard position corresponding to an alignment mark disposed on the object to be aligned, the light receiving device being provided with a plurality of light sensors for sensing light emitting from the light emitting device on an end surface facing the object to be aligned; a processor configured to receive sensing signals transmitted from each of the light sensors and determine whether the object to be aligned is aligned accurately according to whether each of the light sensors sense the light emitted from the light emitting device. This alignment system shortens the processing time and enhances the processing efficiency.

Wafer alignment with restricted visual access has been disclosed. In an example, a method of processing a substrate for fabricating a solar cell involves supporting the substrate over a stage. The method involves forming a substantially opaque layer over the substrate. The substantially opaque layer at least partially covers edges of the substrate. The method involves performing fit-up of the substantially opaque layer to the substrate. The method involves illuminating the covered edges of the substrate with light transmitted through the stage, and capturing a first image of the covered edges of the substrate based on the light transmitted through the stage. The method further includes determining a first position of the substrate relative to the stage based on the first image of the covered edges. The substrate may be further processed based on the determined first position of the substrate under the substantially opaque layer.

A detecting apparatus configured to detect a position of a predetermined pattern on a substrate includes a first detecting system configured to detect a position of a first predetermined pattern in a first field of view, and a second detecting system configured to detect a position of a second predetermined pattern with a smaller shift amount than that of the first predetermined pattern in a second field of view narrower than the first field of view.

For the purposes of measuring structures of a microlithographic mask, a method for capturing absolute positions of structures on the mask and a method for determining structure-dependent and/or illumination-dependent contributions to the position of an image of the structures to be imaged, or of the edges defining this structure, are combined with one another. As a result of this, establishing an edge placement error that is relevant to the exposure of a wafer and, hence, a characterization of the mask can be substantially improved.