An interferometer system may include a stage assembly configured to receive and secure a sample, an illumination source configured to generate an illumination beam, a half-wave plate, one or more shearing prisms to shear the illumination beam into two beamlets along a shearing direction, a reference flat disposed proximate to the sample, a detector assembly, and a controller. The controller may cause the illumination source to generate an illumination beam and sweep the illumination beam across a plurality of wavelengths, and determine both a surface height measurement and a surface slope measurement of the sample based on the illumination received by the detector assembly.

Disclosed is a three-dimensional shape measuring apparatus using a diffraction grating, comprising: a light splitter installed in a traveling direction of a light generated from a light source unit and configured to reflect a portion of the light along a first path and transmit a portion of the light along a second path; an image sensor unit configured to receive a light traveling along the first path and reflected from a measurement target having at least one hole, and measure the shape of the measurement target; and a diffraction grating disposed on at least one light path among a light path between the light source unit and the light splitter, a light path between the measurement target and the light splitter, and a light path between the measurement target and the image sensor unit.

A thickness measurement system may include an illumination source, a beam splitter to split illumination from the illumination source into two beams, a translation stage configured to translate a reference sample along a measurement direction, a first interferometer to generate a first interferogram between a first surface of a test sample and a first surface of the reference sample, and a second interferometer to generate a second interferogram between a second surface of the test sample and a second surface of the reference sample. A thickness measurement system may further include a controller to receive interference signals from the first and second interferometers as the translation stage scans the reference sample, and determine a thickness of the test sample based on the thickness of the reference sample and a distance travelled by the translation stage between peaks of envelopes of the interference signals.

A wafer shape metrology system includes a wafer shape metrology sub-system configured to perform one or more stress-free shape measurements on a first wafer, a second wafer, and a post-bonding pair of the first and second wafers. The wafer shape metrology system includes a controller communicatively coupled to the wafer shape metrology sub-system. The controller is configured to receive stress-free shape measurements from the wafer shape sub-system; predict overlay between one or more features on the first wafer and the second wafer based on the stress-free shape measurements of the first wafer, the second wafer, and the post-bonding pair of the first wafer and the second wafer; and provide a feedback adjustment to one or more process tools based on the predicted overlay. Additionally, feedforward and feedback adjustments may be provided to one or more process tools.

An acquiring apparatus includes a first light source, a measurement optical system, an image sensor, an adjusting unit, an interferometer, and a calculating unit configured to calculate a distance between adjacent target surfaces among the plurality of target surfaces based on an interference signal. The index surface, a surface containing the first point, a surface containing the second point, and the light receiving surface have a conjugate relationship with each other with respect to the measurement optical system.

A method for assessing a wall of a depression, particularly a bore, in a workpiece. The method requires that a light beam in the depression is deflected so that at least two regions of the at least one wall portion are illuminated, and in that, by means of the at least two regions, reflected light is guided along the first axis out of the depression and is used outside the depression for determining the geometry and/or reflectivity of the at least one wall portion. The determination of the geometry or reflectivity is carried out interferometrically and/or wherein in each region for at least 250 pixels, at least one distance value and/or at least one intensity and/or reflectivity value is detected, and/or wherein the regions and/or the at least one light beam each has an area of at least 0.1 mm.sup.2.

A system is disclosed. The system includes a tool cluster. The tool cluster includes a first deposition tool configured to deposit a first layer on a wafer. The tool cluster additionally includes an interferometer tool configured to obtain one or more measurements of the wafer. The tool cluster additionally includes a second deposition tool configured to deposit a second layer on the wafer. The tool cluster additionally includes a vacuum assembly. One or more correctables configured to adjust at least one of the first deposition tool or the second deposition tool are determined based on the one or more measurements. The one or more measurements are obtained between the deposition of the first layer and the deposition of the second layer without breaking the vacuum generated by the vacuum assembly.

Apparatus and methods are described, for detecting the surface topography of a portion of a curved surface of an object. A beam of light is directed toward the surface from a broad angle of incidence with respect to an optical axis of a camera. Light reflected from the surface is received by the camera, via a narrow-angle aperture. One or more darkened regions in the received light are detected, and the surface topography of portion of the surface is detected at least partially in response to the detected darkened regions. Other applications are also described.

The present invention relates to a precision measurement system using an interferometer and an image, comprising: an interferometer for measuring a distance to a movable object by a transfer device; an imaging device which is fixed at a specific position and captures an image of an object located within a specific range; and a control device which calculates absolute coordinates indicating a distance from a reference point to each pixel of the image on the basis of the distance measured by the interferometer and the image obtained by the imaging device, calculates an absolute distance between the pixels of the image on the basis of the absolute coordinates, and measures a length of the object captured by the imaging device using the absolute coordinates or the absolute distance.

A laser interferometer system includes a beam splitter to split a laser beam into first and second beam sets, a first retroreflector mounted to an object to reflect the first beam set, a first detecting device for detecting movements of the object in x-, y- and z-axis directions based on the reflected first beam set, a second retroreflector mounted to the object to reflect the second beam set, and a second detecting device for detecting rotations and movements of the object with respect to the y- and z-axis directions based on the reflected second beam set. The movements of the object in the z-axis direction obtained by the first and second detecting devices are used to obtain a rotation of the object with respect to the x-axis direction.