Embodiments of the present disclosure relate to a metrology method and system for critical dimensions based on a dispersion relation in momentum space. The method comprises: establishing, in accordance with parameters of incident light and a modeled geometric topography of the target to be measured, a simulation dataset associated with a dispersion curve of the target to be measured in momentum space; training a neural-network-based prediction model based on the simulation dataset; obtaining, based on an actual measurement of the target to be measured by incident light, a dispersion relation pattern of the target to be measured in momentum space, wherein the dispersion relation pattern at least indicates a dispersion curve associated with the critical dimensions of the target to be measured; extracting, based on the dispersion relation pattern, features related to the dispersion curve from the dispersion relation pattern via the trained prediction model, to determine an estimated value associated with at least one critical dimension of the target to be measured. According to the method disclosed herein, at least one critical dimension is measured in a more efficient, economical and accurate way.

A system includes an illumination system, an optical element, a switching element and a detector. The illumination system includes a broadband light source that generates a beam of radiation. The dispersive optical element receives the beam of radiation and generates a plurality of light beams having a narrower bandwidth than the broadband light source. The optical switch receives the plurality of light 5 beams and transmits each one of the plurality of light beams to a respective one of a plurality of alignment sensor of a sensor array. The detector receives radiation returning from the sensor array and to generate a measurement signal based on the received radiation.

A lithography apparatus is provided. The lithography apparatus includes a wafer stage configured to secure a semiconductor wafer and having a plurality of electrodes. The lithography apparatus also includes an exposure tool configured to perform an exposure process by projecting an extreme ultraviolet (EUV) light on the semiconductor wafer. The lithography apparatus further includes a controller configured to control power supplied to the electrodes to have a first adjusted voltage during the exposure process for a first group of exposure fields on the semiconductor wafer so as to secure the semiconductor wafer to the wafer stage. The first adjusted voltage is in a range from about 1.6 kV to about 3.2 kV.

A metrology apparatus for determining a characteristic of interest of a structure on a substrate, the apparatus comprising: a radiation source configured to generate illumination radiation; at least two illumination branches comprising at least one optical fiber and configured to illuminate a structure on a substrate from different angles; and a radiation switch configured to receive the illumination radiation and transfer at least part of the radiation to a selectable one of the at least two illumination branches.

A method for aligning to a pattern on a wafer is disclosed. The method includes the steps of obtaining a first inline image from a first sample wafer, obtaining a first contour pattern of an alignment mark pattern from the first inline image, using the first contour pattern to generate a first synthetic image in black and white pixels, using the first synthetic image as a reference to recognize the alignment mark pattern on a tested wafer, and aligning to a tested pattern on the tested wafer according to a position of the alignment mark pattern on the tested wafer and a coordinate information.

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 method for determining an input to a lens model to determine a setpoint for manipulation of a lens of a lithographic apparatus when addressing at least one of a plurality of fields of a substrate, the method including: receiving parameter data for the at least one field, the parameter data relating to one or more parameters of the substrate within the at least one field, the one or more parameters being at least partially sensitive to manipulation of the lens as part of an exposure performed by the lithographic apparatus; receiving lens model data relating to the lens; and determining the input based on the parameter data and on the lens model data.

A method for training a machine learning model to generate a predicted measured image, the method including obtaining (a) an input target image associated with a reference design pattern, and (b) a reference measured image associated with a specified design pattern printed on a substrate, wherein the input target image and the reference measured image are non-aligned images; and training, by a hardware computer system and using the input target image, the machine learning model to generate a predicted measured image.

The present invention relates to a monitor wafer measuring method and measuring apparatus. The monitor wafer measuring method comprises the following steps: fixing a product wafer, the product wafer having several alignment marks and product measuring sites corresponding respectively to the alignment marks; determining the product measuring sites according to the alignment marks; and placing a monitor wafer, a projection of the monitor wafer in a vertical direction being aligned with and coinciding with the product wafer. The present application can reduce or even eliminate positional errors of the monitor wafer during a measurement process, such that product-level measuring position accuracy can be achieved for the monitor wafer and further, the measuring machine itself and process changes can be monitored in a better way.

A recipe selection method includes obtaining measurements from metrology targets, metrology targets positioned on a semiconductor substrate, obtaining measurements from in-device targets, in-device targets positioned on the semiconductor substrate, and determining a recipe for accurate metrology using both metrology target measurements and in-device metrology measurements.