A method for determining one or more optimized values of an operational parameter of a sensor system configured to measure a property of a substrate is disclosed. The method includes: determining a quality parameter for a plurality of substrates; determining measurement parameter values for the plurality of substrates using the sensor system for a plurality of values of the operational parameter; comparing a substrate to substrate variation of the quality parameter and a substrate to substrate variation of a mapping of the measurement parameter values; and determining the one or more optimized values of the operational parameter based on the comparing.

According to one embodiment, a pattern formation method includes holding a substrate on a suction chuck that an outer suction region for an outer edge portion of the substrate and an inner suction region for an inner region of the substrate. A partial shot region at an outer edge of the substrate has a first alignment mark in the inner region and a second alignment mark at the outer edge portion. While a template is being pressed against a resin film in the shot region, position alignment using the second and fourth alignment marks is performed by adjusting a suction force for the outer suction region for changing a warpage amount of the substrate while observing the second and fourth alignment marks through the template.

The invention relates to a method for measuring a photomask for semiconductor lithography, including the following steps: recording an aerial image of at least one region of the photomask, defining at least one region of interest, ascertaining structure edges in at least one region of interest, providing desired structures to be produced by the photomask, adapting the ascertained structure edges to the desired structures, and displacing the adapted structure edges by means of the results of a separate registration measurement.

A method includes receiving a wafer, defining a plurality of zones over the wafer, performing a multi-zone alignment compensation for each of the plurality of zones according to an equation along a first direction to obtain a plurality of compensation values for each of the plurality of zones, and performing a wafer alignment and a lithography exposure for each of the plurality of zones according to the plurality of compensation values. The wafer alignment and the lithography exposure are performed zone-by-zone.

An alignment system obtains the characteristics of the light coming back from a wafer stack. A beam analyzer measures changes in wavelength, polarization, and beam profile. This measured information allows for in-line process variation corrections. The correction provides optical monitoring of individual mark stack variations, and in turn provides information to reduce individual mark process variation-induced accuracy error.

A method for forming an aligned mask comprises etching a reference mark on a substrate to demarcate a boundary of an etch region; forming an etch mask on the substrate, using an exposure setting, the etch mask having a boundary; and measuring a distance between the reference mark and the boundary. When the measured distance is outside a margin of a target distance, then the etch mask is removed from the substrate, the exposure setting is changed, a next etch mask is formed using the changed exposure setting, and said measuring is repeated. A set of reference marks can be etched on a top level in a set of levels to demarcate boundaries of etch regions. An etch-trim process can be performed to form steps in the set of levels, wherein the etch-trim process includes at least first and second etch-trim cycles using first and second reference marks.

A method includes receiving a wafer, measuring a surface topography of the wafer; calculating a topographical variation based on the surface topography measurement performing a single-zone alignment compensation when the topographical variation is less than a predetermined value or performing a multi-zone alignment compensation when the topographical variation is greater than the predetermined value; and performing a wafer alignment according to the single-zone alignment compensation or the multi-zone alignment compensation.

A method of processing a wafer is provided. The method includes providing a reference pattern for patterning a wafer. The reference pattern is independent of a working surface of the wafer. A placement of a first pattern on the working surface of the wafer is determined by identifying the reference pattern to align the first pattern. The first pattern is formed on the working surface of the wafer based on the placement.

Polarized light emitted from a light source and transmitted through a light transmission region formed in a mask is radiated onto an exposure target object placed on a stage. The polarized light is radiated onto the exposure target object from a direction inclined by approximately 50 to approximately 70 in relation to a direction that is substantially orthogonal to a top surface of the stage.

A photolithography system includes a light source, a photomask stage, a projection optical system and a wafer stage, and the projection optical system includes an anamorphic lens. In a photolithography method, a wafer and a photomask are mounted on the wafer stage and the photomask stage, respectively, and a first exposure process is performed using the photomask to transfer layouts of patterns included in the photomask to a first half field of the wafer. A relative position of the photomask with respect to the wafer is changed, and a second exposure process is performed to transfer the layouts of the patterns included in the photomask to a second half field of the wafer.