An apparatus for detecting a surface condition of an object. The apparatus comprises a light source, a reflective face and an imaging device. The imaging device is configured to receive reflected light emanating from the reflective face. The reflective face is oriented at a first acute angle relative to an optical axis of the imaging device, such that a projection area of a virtual image of a surface formed via the reflective face is greater than a projection area of the surface on a plane perpendicular to the optical axis.

An apparatus for detecting a surface condition of an object. The apparatus comprises a light source, a reflective face and an imaging device. The imaging device is configured to receive reflected light emanating from the reflective face. The reflective face is oriented at a first acute angle relative to an optical axis of the imaging device, such that a projection area of a virtual image of a surface formed via the reflective face is greater than a projection area of the surface on a plane perpendicular to the optical axis.

A learning data generation device that can generate learning data suitable for learning of an identification model. The learning data generation device has a function of cutting out part of first image data as second image data, a function of generating a two-dimensional graphic corresponding to the area of the second image data and representing a pseudo defect, a function of generating third image data by combining the second image data and the two-dimensional graphic, and a function of assigning a label corresponding to the two-dimensional graphic to the third image data. By using the third image data for learning of the identification model, a highly accurate identification model can be generated.

An arrangement of a 3D measurement device according to the invention comprises an image source in order to produce consecutive images on a surface of an object, a camera to take pictures of the surface, and a processor unit in order to compare the pictures of the camera with said images. The arrangement comprises also a first area and a second area on the images. The arrangement further comprises at least one double detector in order to detect the illuminated first area and the illuminated second area, and a drive unit in order to trigger at least one camera. The drive unit is arranged to trigger the camera if the double detector indicates that a state of the first area changes and a state of the second area changes.

Apparatus and methods for forming an image of an object which involves focusing partially to fully spatially-coherent radiation onto a sample and collecting the resulting scattered radiation (the “standard data set”) on an array detector. In addition to the standard dataset, an additional measurement or plurality of measurements is made of a relatively-unscattered beam, using the array detector, which comprises the “modulus enforced probe (MEP) dataset”. This MEP dataset serves as an extra constraint, called the MEP constraint, in the phase retrieval algorithm used to reconstruct the image of the object.

Apparatus and methods for forming an image of an object which involves focusing partially to fully spatially-coherent radiation onto a sample and collecting the resulting scattered radiation (the “standard data set”) on an array detector. In addition to the standard dataset, an additional measurement or plurality of measurements is made of a relatively-unscattered beam, using the array detector, which comprises the “modulus enforced probe (MEP) dataset”. This MEP dataset serves as an extra constraint, called the MEP constraint, in the phase retrieval algorithm used to reconstruct the image of the object.

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.

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.

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.