Methods for manufacturing a semiconductor structure are provided. A substrate is provided. A metrology target is formed in a layer over the substrate according to a first layer mask and a second layer mask. The metrology target includes a first pattern formed by a plurality of first photonic crystals corresponding to the first layer mask and a second pattern formed by a plurality of second photonic crystals corresponding to the second layer mask. First light is provided to illuminate the metrology target. Second light is received from the metrology target in response to the first light. The second light is analyzed to detect overlay-shift between the first pattern and the second pattern. The first pattern and the second pattern are arranged to cross in one direction in the metrology target.

A method of determining a position of a feature (for example an alignment mark) on an object (for example a silicon wafer) is disclosed. The method comprises determining an offset parameter, determining the second position; and determining a first position from the second position and the offset parameter, the position of the mark being the first position. The offset parameter is a measure of a difference in: a first position that is indicative of the position of the feature; and a second position that is indicative of the position of the feature. The offset parameter may be determined using a first measurement apparatus and the second position may be determined using a second, different measurement apparatus.

Methods of fabricating and using an overlay mark are provided. In some embodiments, the overlay mark includes an upper layer and a lower layer disposed below the upper layer. The lower layer includes a first plurality of compound gratings extending in a first direction and disposed in a first region of the overlay mark, each of the first plurality of compound gratings including one first element and at least two second elements disposed on one side of the first element, and a second plurality of compound gratings extending the first direction and disposed in a second region of the overlay mark, each of the second plurality of compound gratings including one third element and at least two fourth elements on one side of the third element. The first plurality of compound gratings is a mirror image of the second plurality of compound gratings.

A method of measuring overlay uses a plurality of asymmetry measurements from locations (LOI) on a pair of sub-targets (1032, 1034) formed on a substrate (W). For each sub-target, the plurality of asymmetry measurements are fitted to at least one expected relationship (1502, 1504) between asymmetry and overlay, based on a known bias variation deigned into the sub-targets. Continuous bias variation in one example is provided by varying the pitch of top and bottom gratings (P1/P2). Bias variations between the sub-targets of the pair are equal and opposite (P2/P1). Overlay (OV) is calculated based on a relative shift (xs) between the fitted relationships for the two sub-targets. The step of fitting asymmetry measurements to at least one expected relationship includes wholly or partially discounting measurements (1506, 1508, 1510) that deviate from the expected relationship and/or fall outside a particular segment of the fitted relationship.

A resonant amplitude grating mark has a periodic structure configured to scatter radiation incident on the mark. The scattering is mainly by coupling of the incident radiation to a waveguiding mode in the periodic structure. The effective refractive indexes and lengths of portions of the periodic structure are configured to provide an optical path length of the unit cell in the direction of periodicity that essentially equals an integer multiple of a wavelength present in the radiation. The effective refractive indexes and lengths of the portions are also configured to provide an optical path length of the second portion in the direction of periodicity that is selected from 0.30 to 0.49 of the wavelength present in the spectrum of the radiation.

Overlay-shift measurement systems are provided. An overlay-shift measurement system includes an optical device, a first light detection device and a processor. The optical device is configured to provide an input light to a metrology target of a semiconductor structure. The first light detection device is configured to receive a transmitted light from the metrology target when the input light penetrates the metrology target. The processor is configured to determine whether overlay-shift between a plurality of first photonic crystals and a plurality of second photonic crystals in the metrology target is present according to characteristics of the transmitted light.

The present invention provides a measurement apparatus for measuring a position of a first pattern and a position of a second pattern provided in a target object, the apparatus including an image capturing unit including a plurality of pixels which detect light from the first pattern and light from the second pattern, and configured to form an image capturing region used to capture the first pattern and the second pattern by the plurality of pixels, and a control unit configured to adjust the image capturing unit such that a relative ratio of an intensity of a detection signal of the first pattern generated based on an output from a first image capturing region and an intensity of a detection signal of the second pattern generated based on an output from a second image capturing region falls within an allowable range.

A target for use in the measurement of misregistration between layers formed on a wafer in the manufacture of semiconductor devices, the target including a first pair of periodic structures (FPPS) and a second pair of periodic structures (SPPS), each of the FPPS and the SPPS including a first edge, a second edge, a plurality of first periodic structures formed in a first area as part of a first layer and having a first pitch along a first pitch axis, the first pitch axis not being parallel to either of the first edge or second edge, and a plurality of second periodic structures formed in a second area as part of a second layer and having the first pitch along a second pitch axis, the second pitch axis being generally parallel to the first pitch axis.

A method for manufacturing semiconductor mark includes: providing a pattern having a peripheral edge corrected by Optical Proximity Correction (OPC); cutting multiple independent alignment sections from the pattern; and splicing the multiple alignment sections to form a semiconductor mark having a peripheral edge corrected by OPC.

A display device includes: an optical member including a plurality of lenses and a first alignment mark disposed to overlap at least one lens of the plurality of lenses; and a display panel including a plurality of subpixels and a second alignment mark disposed between the plurality of subpixels and overlapping the first alignment mark, wherein each of the first alignment mark and the second alignment mark includes a magnetic substance.