Aspects of the present disclosure provide a method of aligning a wafer pattern. For example, the method can include providing a wafer having a reference pattern located below a front side of the wafer, and directing a light beam to the wafer. The method can further include identifying at least one of power and a wavelength of the light beam such that the light beam is capable of passing through the wafer and reaching the reference pattern, or identifying at least one of power and a wavelength of the light beam based on at least one of a material of the wafer and a depth of the reference pattern below the front side of the wafer. The method can further include using the light beam to image the reference pattern.

Aspects of the present disclosure provide an inspection system, which can include an image module and processing circuitry. The imaging module can image a wafer with a first light beam and a second light beam. The first light beam can be coaxially aligned with the second light beam, and image a first pattern located on a front side of a wafer to form a first image. The second light beam can image a second pattern located below the first pattern to form a second image via quantum tunneling imaging or infrared transmission imaging. The second light beam can have power sufficient to pass through at least a portion of a thickness of the wafer and reach the second pattern. The processing circuitry can perform image analysis on the first image and the second image to calculate an overlay value of the first and second patterns and/or defects of the wafer.

Aspects of the present disclosure provide an imaging system. For example, in the imaging system a first light source can generate a first light beam of a first wavelength, a second light source can generate a second light beam of a second wavelength, the second light beam having power sufficient to pass through at least a portion of a thickness of a wafer, an alignment module can coaxially align the second light beam with the first light beam, a coaxial module can focus the coaxially aligned first and second light beams onto a first pattern located on a front side of the wafer and a second pattern located below the first pattern, respectively, and an image capturing module can capture a first image of the first pattern and a second image of the second pattern. The second image can be captured via quantum tunneling imaging or infrared (IR) transmission imaging.

A method of pattern alignment is provided. The method includes identifying a reference pattern positioned below a working surface of a wafer. The wafer is exposed to a first pattern of actinic radiation. The first pattern is a first component of a composite pattern. The first pattern of actinic radiation is aligned using the reference pattern. The wafer is exposed to a second pattern of actinic radiation. The second pattern is a second component of the composite pattern and exposed adjacent to the first pattern. The second pattern of actinic radiation is aligned with the first pattern of actinic radiation using the reference pattern.

A detection apparatus includes an image pickup unit and a processor which detects a position of a mark using a two-dimensional image of the mark. The processor generates a one-dimensional signal having a plurality of peaks by accumulating images included in a detection region, detects peaks in which differences between values of the peaks and a reference value are equal to or larger than a threshold value and peaks in which differences between values of the peaks and the reference value are smaller than the threshold value from among the plurality of generated peaks and obtains a failure region in the mark, resets the detection region such that the differences between the values of the detected peaks and the reference value become smaller than the threshold value, generates a one-dimensional signal by accumulating images included in the reset detection region, and detects a position of the mark.

A method of manufacturing a display device including: preparing a substrate having a display area and a non-display area; and forming an alignment mark disposed in the non-display area of the substrate. The alignment mark includes a quadrangular-shaped center portion and a plurality of measurement portions that surround the center portion, the plurality of measurement portions including four or more measurement portions, and each of the measurement portions including sides that are parallel with two sides of the quadrangular-shaped center portion.

An exposure device that draws a pattern on a substrate by shining a beam from a light source device on substrate and scanning the beam in a main scanning direction while varying the intensity of beam according to pattern information, including: a scanning unit having a beam scanning unit that includes a polygonal mirror whereby the beam is oriented to scan the beam, and light detector for photoelectric detection of reflected light generated when beam is shined on substrate; an electro-optical element for controlling the beam's intensity modulation according to pattern information such that at least part of second pattern to be newly drawn is drawn on top of at least part of first pattern formed on substrate; and a measurement unit measuring relative positional relationship between the first and second pattern on the basis of a detection signal output by the detector while second pattern is drawn on substrate.

A measurement system used in a manufacturing line for micro-devices includes: a plurality of measurement devices in which each device performs measurement processing on a substrate; and a carrying system to perform delivery of a substrate with the plurality of measurement devices. The plurality of measurement devices includes a first measurement device that acquires position information on a plurality of marks formed on a substrate, and a second measurement device that acquires position information on a plurality of marks formed on a substrate. Position information on a plurality of marks formed on a substrate can be acquired under a setting of a first predetermined condition in the first measurement device, and position information on a plurality of marks formed on another substrate can be acquired under a setting of a second predetermined condition different from the first predetermined condition in the second measurement device.

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.

Disclosed is a lithography process on a sample including at least one structure and covered by at least a lower layer of resist and a upper layer of resist the process including: using an optical device to image or determine, in reference to the optical device, a position of the selected structure and positions of markers integral with the sample; using an electron-beam device, imaging or determining the position of each marker in reference to the electron-beam device; deducing the position of the selected structure in reference to the electron-beam device; exposing to an electron beam the upper layer of resist above the position of the selected structure to remove all the thickness of the upper layer of resist above the position of the selected structure but none or only part of the thickness of the lower layer of resist above the position of the selected structure.