A method for characterising high aspect ratio (HAR) structures etched in a substrate includes, for at least one structure, an interferometric measurement step, carried out with a low-coherence interferometer positioned on a top surface of the substrate, for measuring with a measurement beam, at least one depth data relating to a depth of the HAR structure, and a first adjusting step for adjusting a diameter, at the top surface, of the measurement beam according to at least one top critical dimension (top-CD) data relating to a width of the HAR structure.

A method and system implementing the method for characterising structures etched in a substrate, such as a wafer, includes at least one structure etched in the substrate, an imaging step including the following steps: capturing, with an imaging device positioned on the top surface of the substrate, at least one image of a top surface of the substrate, and measuring a first data relating to the structure from at least one captured image, at least one interferometric measurement step, carried out with a low-coherence interferometer positioned on the top surface, for measuring with a measurement beam positioned on the structure, at least one depth data relating to a depth of the structure; and a first adjusting step for adjusting the measurement beam according to the first data.

A test appliance and a method for testing a mirror, e.g., a mirror of a microlithographic projection exposure apparatus. The test appliance has a computer-generated hologram (CGH), and a test can be carried out on at least a portion of the mirror by way of an interferometric superposition of a test wave that is directed onto the mirror by this computer-generated hologram and a reference wave. Here, the computer-generated hologram (CGH) (120, 320) is designed in such a way that, during operation of the appliance, it provides a first test wave for testing a first portion of the mirror (101, 301) by interferometric superposition with a reference wave in a first position of the mirror (101, 301) and at least a second test wave for testing a second portion of the mirror (101, 301) by interferometric superposition with a reference wave in a second position of the mirror (101, 301).

The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

A measurement apparatus includes a filter changing a light amount of an irradiation light, a lens irradiating a surface of a material with the irradiation light, a stage changing a focus position of the irradiation light in a depth direction of the material, an interfering light extractor causing the irradiation light to interfere with reflected light from the material, a detector detecting an intensity of interfering light obtained by interference between the irradiation light and the reflected light, and a controller calculating a height of the surface of the material based on the detected intensity of interfering light while changing a relative focus position of the irradiation light with respect to the material at a given measurement point of the surface of the material. The controller controls the filter or light source based on the detected intensity of interfering light to change the light amount of the irradiation light.

A method and an apparatus for detecting a concave cylinder and a cylindrical diverging lens are disclosed. In particular, a method for non-contact interference detection of a cylindrical shape is disclosed. A cylindrical converging lens and a cylindrical diverging lens are combined with a to-be-tested concave cylinder respectively. Wavefront error data of the combination of the cylindrical diverging lens and the to-be-tested concave cylinder and wavefront error data of the combination of the cylindrical converging lens and the to-be-tested concave cylinder are obtained through interference measurement respectively. Wavefront error data of a combination of the cylindrical diverging lens and the cylindrical converging lens is then obtained through interference measurement. Shape error data of the to-be-tested concave cylinder, the cylindrical diverging lens, and the cylindrical converging lens is obtained respectively by using a difference algorithm and a wavefront recovery algorithm.

The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

A method and an apparatus for detecting a cylinder and a cylindrical converging lens are disclosed. In particular, a method for non-contact interference detection of a cylindrical shape is disclosed. Two converging lenses which modulate parallel light into cylindrical waves are combined with a to-be-tested cylinder respectively. Wavefront error data of the combination of the converging lens and the to-be-tested cylinder and wavefront error data of the combination of the two cylindrical converging lenses are obtained. Shape error data of the to-be-tested cylinder, the two cylindrical converging lenses is obtained respectively by using a difference algorithm and a wavefront recovery algorithm. In the technical solution, a detection light path is simple, and shape detection of a cylinder with relatively high precision can be implemented without using a high-precision detection tool calibrated in advance. The technical solution is particularly suitable for cylinder processing in the field of optical processing.

An apparatus includes a number of photonic integrated circuit (PIC) imaging detector arrays, and multiple electronic integrated circuits (ICs) coupled to the PIC imaging detector arrays. Each PIC imaging detector array of includes a number of lenslets and a number of waveguides. At least some of the lenslets are coupled to multiple waveguides, and sets of two lenslets are configured to form interferometer channels.

The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.