Disclosed is a method of metrology. The method comprises illuminating a radiation onto a substrate; obtaining measurement data relating to at least one measurement of each of one or more structures on the substrate; using a Fourier-related transform to transform the measurement data into a transformed measurement data; and extracting a feature of the substrate from the transformed measurement data, or eliminating an impact of a nuisance parameter.

According to example embodiments, there is provided a photoresist inspection method. The photoresist inspection method includes: providing a photoresist on a substrate; irradiating the photoresist with an electron beam and an excitation beam; detecting fluorescent light generated by the photoresist in response to the excitation beam; and evaluating the photoresist based on the fluorescent light.

A reticle inspection system may include two or more inspection tools to generate two or more sets of inspection images for characterizing a reticle, where the two or more inspection tools include at least one reticle inspection tool providing inspection images of the reticle. The reticle inspection system may further include a controller to correlate data from the two or more sets of inspection images to positions on the reticle, detect one or more defects of interest on the reticle with the correlated data as inputs to a multi-input defect detection model, and output defect data associated with the defects of interest.

Disclosed is an illumination source for generating measurement radiation for an inspection apparatus. The source generates at least first measurement radiation and second measurement radiation such that the first measurement radiation and the second measurement radiation interfere to form combined measurement radiation modulated with a beat component. The illumination source may be a HHG source. Also disclosed is an inspection apparatus comprising such a source and an associated inspection method.

An apparatus and a method for correctly measuring a phase of an extreme ultraviolet (EUV) mask and a method of fabricating an EUV mask including the method are described. The apparatus for measuring the phase of the EUV mask includes an EUV light source configured to generate and output EUV light, at least one mirror configured to reflect the EUV light as reflected EUV light incident on an EUV mask to be measured, a mask stage on which the EUV mask is arranged, a detector configured to receive the EUV light reflected from the EUV mask, to obtain a two-dimensional (2D) image, and to measure reflectivity and diffraction efficiency of the EUV mask, and a processor configured to determine a phase of the EUV mask by using the reflectivity and diffraction efficiency of the EUV mask.

In accordance with some embodiments of the present disclosure, an inspection method of a photomask includes performing a first inspection process, unloading the photomask from the inspection system, and performing a second inspection process. In the first inspection process, a common Z calibration map of an objective lens of an optical module with respect to the photomask is generated and stored, and a first image of the photomask is captured by using an image sensor while focusing the objective lens of the optical module based on the common Z calibration map. The photomask is unloaded from the inspection system. In the second inspection process, the photomask is loaded on the inspection system and a second image of the photomask is captured by using an image sensor while focusing an objective lens of an optical module based on the common Z calibration map generated in the first inspection process.

A pattern inspection apparatus includes an illumination optical system to illuminate an inspection substrate on which a pattern is formed, an offset calculation circuit to calculate an offset amount which depends on an image accumulation time of each of a plurality of photo sensor elements arrayed two-dimensionally, a time delay integration (TDI) sensor to include the plurality of photo sensor elements, to acquire an image of the inspection substrate by receiving a transmitted light or a reflected light from the inspection substrate by the plurality of photo sensor elements, to correct, using the offset amount, a pixel value of optical image data of an acquired image, and to output the optical image data having been corrected, and a comparison circuit to compare an optical image formed by the optical image data output from the TDI sensor with a reference image.

An image acquisition method includes storing a coefficient of a relational expression between a parameter corresponding to a light quantity incident on an imaging sensor including a photo sensor element and an output value of the imaging sensor in the case of the light incident on the imaging sensor which employs a reference image accumulation time, inputting a desired image accumulation time, and calculating a parameter for obtaining a desired output value of the imaging sensor by using a corrected relational expression obtained by correcting using an output value of the imaging sensor employing the desired image accumulation time in the case of the incident light quantity being zero, adjusting the light quantity incident on the imaging sensor to be a calculated parameter, and acquiring a target image by the imaging sensor on which an adjusted light quantity is incident, and outputting data of the acquired image.

A method of inspection for defects on a substrate, such as a reflective reticle substrate, and associated apparatuses. The method includes performing the inspection using inspection radiation obtained from a high harmonic generation source and having one or more wavelengths within a wavelength range of between 20 nm and 150 nm. Also, a method including performing a coarse inspection using first inspection radiation having one or more first wavelengths within a first wavelength range; and performing a fine inspection using second inspection radiation having one or more second wavelengths within a second wavelength range, the second wavelength range comprising wavelengths shorter than the first wavelength range.

An EUV reflectometer includes a radiation source, a beam shaping unit (130) generating a measurement beam (190) from the radiation; a positioning device (500) for holding and positioning a test object (110) relative to the measurement beam in plural degrees of freedom; and a detector that detects the EUV radiation reflected by the test object. The positioning device has a main carrier (520), which is rotatable about a vertical rotation axis and on which a parallel kinematic multi-axis system (530) having a multiplicity of actuators is arranged. A common platform (540) movable in three linear and three rotational degrees of freedom carries a holding device (550) for holding the test object and a rotary drive for rotating the holding device about a rotation axis. An associated measuring system (700) determines the location and position of the test object in space and/or in relation to the measurement beam.