Embodiments described herein provide a method for cleaning contamination from sensors in a lithography tool without requiring recalibrating the lithography tool. More particularly, embodiments described herein teach cleaning the sensors using hydrogen radicals for a short period while the performance drifting is still above the drift tolerance. After a cleaning process described herein, the lithography tool can resume production without recalibration.

A lithographic apparatus including: a projection system to project radiation onto a substrate supported on a substrate stage, during an exposure phase; a sensing system to sense a property of the substrate on the stage during a sensing phase; and a positioning system to determine a position of the stage relative to a reference system via a radiation path between the stage and the reference system, wherein the apparatus is configured to control stage movement relative to the reference system in the sensing phase and to control other movement relative to the reference system during the exposure phase; the stage or reference system having an outlet to provide a gas curtain to reduce ingress of ambient gas into the path; and the apparatus is operative such that a characteristic of the gas curtain is different in at least part of the sensing phase compared to in the exposure phase.

A pre-alignment system includes a common object lens group configured to collect diffracted beams from a patterning device, wherein the common object lens group is further configured to produce telecentricity in an object space of the pre-alignment system. The pre-alignment system also includes a multipath sensory array having at least one image lens system, wherein the at least one image lens system includes a telecentric converter lens configured to produce telecentricity in an image space of the pre-alignment system.

An apparatus and method for performing a measurement operation on a substrate in accordance with one or more substrate alignment models. The one or more substrate alignment models are selected from a plurality of candidate substrate alignment models. The apparatus, which may be a lithographic apparatus, includes an external interface which enables selection of the substrate alignment model(s) and/or alteration of the substrate alignment model(s) prior to the measurement operation.

An imprint lithography alignment method includes assessing a first alignment error between the template and the substrate, generating a first input signal corresponding to a first relative motion between the template and the substrate, initiating the first relative motion between the template and the substrate via the first input signal, assessing an output signal corresponding to the first relative motion, comparing the first input signal and the output signal to yield a motion control action corresponding to a second relative motion between the template and the substrate, generating a second input signal corresponding to the second relative motion between the template and the substrate, initiating the second relative motion between the template and the substrate via the second input signal, and assessing a second alignment error between the template and the substrate, wherein a magnitude of the first alignment error exceeds a magnitude of the second alignment error.

In order to improve the throughput performance and/or economy of a measurement apparatus, the present disclosure provides a metrology apparatus including: a first measuring apparatus; a second measuring apparatus; a first substrate stage configured to hold a first substrate and/or a second substrate; a second substrate stage configured to hold the first substrate and/or the second substrate; a first substrate handler configured to handle the first substrate and/or the second substrate; and a second substrate handler configured to handle the first substrate and/or the second substrate, wherein the first substrate is loaded from a first, second or third FOUP, wherein the second substrate is loaded from the first, second or third FOUP, wherein the first measuring apparatus is an alignment measuring apparatus, and wherein the second measuring apparatus is a level sensor, a film thickness measuring apparatus or a spectral reflectance measuring apparatus.

An alignment system configured to be substantially insensitive to thermal variations in its system during alignment measurements. The alignment system includes a sensor system, a support structure, a sensing element, a position measurement system, and an athermal interface between the sensing element and the support structure. The sensor system is configured to determine a in position of an alignment mark on a substrate and the support structure is configured to support the sensor system. The sensing element is configured to detect an unintentional displacement of the support structure and the position measurement system is configured to measure the unintentional displacement relative to a reference element based on the detected unintentional displacement. The athermal interface is configured to prevent detection of temperature induced displacement of the support structure by the sensing element.

Provided herein are approaches for processing reticle blanks. In one approach, a reticle processing system includes a support assembly having a plate coupled to a frame, and a carrier assembly coupled to the support assembly. In one approach, the carrier assembly includes a carrier base coupled to the plate, a reticle disposed over the carrier base, and a carrier shield disposed over the reticle, wherein the carrier shield may include a central opening formed therein, allowing for placement and extraction of the reticle. In one approach, when the carrier assembly is placed atop the support assembly, a plurality of pins extend from the plate through corresponding openings in the carrier base, the plurality of pins supporting the carrier assembly so the carrier base, the reticle, and the carrier shield are each independently supported and vertically separated from one another.

An imprint lithography alignment method includes assessing a first alignment error between the template and the substrate, generating a first input signal corresponding to a first relative motion between the template and the substrate, initiating the first relative motion between the template and the substrate via the first input signal, assessing an output signal corresponding to the first relative motion, comparing the first input signal and the output signal to yield a motion control action corresponding to a second relative motion between the template and the substrate, generating a second input signal corresponding to the second relative motion between the template and the substrate, initiating the second relative motion between the template and the substrate via the second input signal, and assessing a second alignment error between the template and the substrate, wherein a magnitude of the first alignment error exceeds a magnitude of the second alignment error.

While a wafer stage moves linearly in a Y-axis direction, surface position information of a wafer surface at a plurality of detection points set at a predetermined interval in an X-axis direction is detected by a multipoint AF system, and by a plurality of alignment systems arranged in a line along the X-axis direction, marks at different positions on the wafer are each detected, and a part of a chipped shot of the wafer is exposed by a periphery edge exposure system. This allows throughput to be improved when compared with the case when detection operation of the marks, detection operation of the surface position information (focus information), and periphery edge exposure operation are performed independently.