A method for thinning a wafer is provided. The method includes placing a wafer on a support assembly, and the support assembly includes a plurality of pin. The method includes securing an etching mask to a backside of the wafer, and the etching mask has an extending portion which covers a peripheral portion of the wafer. The etching mask has a plurality of circular bores extended along a vertical direction, and the etching mask is secured to the support assembly by connecting the circular bores and the pins. The method also includes performing a wet etching process on the backside of the wafer to foil a thinned wafer, wherein the thinned wafer has a peripheral portion with a first thickness and a central portion having a second thickness smaller than the first thickness.

An alignment system includes a light source for emitting a light. An alignment mark is disposed on a substrate for receiving the light. The alignment mark includes a first pattern and a second pattern disposed on the substrate. The first pattern includes a first region and a second region. The second pattern includes a third region and a fourth region. The first region and the third region are symmetrical with respective to a symmetrical axis. The second region and the fourth region are symmetrical with respective to the symmetrical axis. The first region includes first mark lines parallel to each other. The second region includes second mark lines parallel to each other. A first pitch is disposed between the first mark lines adjacent to each other. A second pitch is disposed between the second mark lines adjacent to each other. The first pitch is different from the second pitch.

Methods and apparatuses for aligning masks with substrates are provided. A method can include receiving a carrier having a substrate disposed thereon at an alignment stage of an alignment module, transferring a mask from a mask cassette of a mask stocker of the alignment module to a position over the alignment stage, and positioning the mask on the carrier. The method can also include acquiring one or more images of the mask and the substrate, where the mask contains one or more alignment holes passing through the mask and the substrate contains one or more alignment dots disposed on an upper surface of the substrate, analyzing the one or more images to determine one or more differences between one or more alignment holes of the mask and one or more alignment dots on the substrate, and aligning the mask with the substrate based on the differences.

A pellicle removal tool including a stage that holds a photomask and an associated pellicle, two or more arms positioned around the stage and configured to engage pellicle side wells of the pellicle, and two or more actuators each configured to adjust at least a vertical position of a corresponding one of the two or more arms so as to apply a lifting force to the pellicle for removal of the pellicle from the photomask.

A method includes aligning and positioning a carrier in a predetermined orientation and location within a first front opening pod (FOUP) of a cluster tool, transferring the carrier to a charging station of the cluster tool, transferring a substrate from a second front opening pod (FOUP) of the cluster tool to the charging station and chucking the substrate onto the carrier, transferring the carrier having the substrate thereon from the charging station to a factory interface of the cluster tool, aligning the carrier having the substrate thereon in the factory interface of the cluster tool such that during substrate processing within a processing platform of the cluster tool the carrier is properly oriented and positioned relative to components of the processing platform, where the processing platform comprises one or more processing chambers, transferring the aligned carrier having the substrate thereon from the factory interface to the processing platform of the cluster tool for substrate processing, and transferring the aligned carrier having the processed substrate thereon from the processing platform to the factory interface.

A metrology system and metrology methods are disclosed. The metrology system comprises a set of device features on a first layer of a sample, a first set of target features on a second layer of the sample and overlapping the set of device features, and a second set of target features on the second layer of the sample and overlapping the set of device features. Relative positions of a first set of Moiré fringes and a second set of Moiré fringes indicate overlay error between the first layer of the sample and the second layer of the sample.

Disclosed are an alignment mask, a metal mask assembly, and a preparation method therefor. The alignment mask includes a mask body. The mask body includes: multiple alignment holes; and, separating parts surrounding at least some alignment holes and used for separating the areas at where the at least some alignment holes are located from other areas, where the separation parts include at least one semi-etched line.

Techniques are disclosed for optical distortion reduction in projection systems for scanning projection and/or lithography. A projection system includes an illumination system configured to generate illumination radiation for generating an image of an object to be projected onto an image plane of the projection system. The illumination system includes a field omitting illumination condenser configured to receive the illumination radiation from a radiation source and provide a patterned illumination radiation beam to generate the image of the object, wherein the patterned illumination radiation beam comprises an omitted illumination portion corresponding to a ridge line of a roof prism disposed within an optical path of the projection system.

An apparatus for processing a substrate in a vacuum chamber is described. The apparatus includes a first carrier transport system for transporting a first carrier along a first transport path in a first direction and a second carrier transport system for transporting a second carrier along a second transport path in the first direction. Further, the apparatus includes a measurement system for measuring a distance between the first carrier and the second carrier. The distance is perpendicular to the first direction.

A micro device transfer apparatus and a micro device transfer method are provided. The micro device transfer apparatus comprises a stage unit including a stage where a target substrate is to be disposed, a plurality of transfer head units disposed above the stage, and a transfer head unit moving part configured to move the plurality of transfer head units, wherein, the transfer head unit comprises a carrier substrate fastening part configured to fasten a carrier substrate where a plurality of micro devices are disposed, a mask unit disposed above the carrier substrate fastening part, the mask unit comprising a mask including an opening part and a shielding part, a light emitting part disposed on the mask unit, and a housing formed around the carrier substrate fastening part, the mask unit, and the light emitting part.