A semiconductor equipment architecture WGT for wafer shape and flatness measurement is disclosed. The semiconductor equipment architecture WGT includes a reflective air-bearing chuck and a hybrid wafer thickness gauge. Also disclosed are the corresponding methods of measuring wafer shape and flatness using the architecture, the air-bearing chuck and the hybrid wafer thickness gauge.

A semiconductor equipment architecture WGT for wafer shape and flatness measurement is disclosed. The semiconductor equipment architecture WGT includes a reflective air-bearing chuck and a hybrid wafer thickness gauge. Also disclosed are the corresponding methods of measuring wafer shape and flatness using the architecture, the air-bearing chuck and the hybrid wafer thickness gauge.

Provided is a method for calibrating an error of installation of an interferometer in a multi-axis laser displacement measurement system, including: adding one or more redundant interferometers in a laser interferometer displacement measurement system; then establishing displacement calculating equations containing installation error of the laser interferometer and obtaining redundant measurement information by continuously measuring displacement information of multiple points, wherein the number of the combined displacement calculating equations is equal to the number of unknown quantities; and further solving the equation set to obtain the installation error of the interferometer. With a redundant arrangement of the laser interferometer, self-calibration of the installation error thereof can be achieved. A problem of difficulty in calibration of the installation error of the multi-axis interferometer in industrial application can be solved without assistance of other displacement sensors with higher precision.

In a method for calibrating an interferometer (100) having a beam path for a measuring beam (112), wherein at least one plane (320) that at least partially reflects the measuring beam (112) has been introduced into the beam path, and wherein a normal to a first plane (320) is inclined at a first angle to a measuring beam (112) incident on the first plane (320), the following steps are carried out: interferometric measurement of a first axial spacing of a first point on the first plane (320) with the measuring beam (112), and interferometric measurement of a second axial spacing of a second point on one of the at least one plane (320) with the measuring beam (112), wherein the second point is spaced apart from the first point.

An analysis apparatus includes an acquisition part that acquires a plurality of interference images based on lights having a plurality of different wavelengths from an interference measurement apparatus, a removing part that outputs an interference component by removing a non-interference component included in an interference signal for each pixel in the plurality of the interference images, a conversion part that generates an analysis signal by performing a Hilbert transformation on the interference component, and a calculation part that calculates a distance between a reference surface and a surface of an object to be measured by specifying a phase gradient of a wavelength of light radiated onto the reference surface and the surface of the object to be measured on the basis of the interference component and the analysis signal.

The invention generally relates to methods for manually calibrating imaging systems such as optical coherence tomography systems. In certain aspects, an imaging system displays an image showing a target and a reference item. A user looks at the image and indicates a point within the image near the reference item. A processor detects an actual location of the reference item within an area around the indicated point. The processor can use an expected location of the reference item with the detected actual location to calculate a calibration value and provide a calibrated image. In this way, a user can identify the actual location of the reference point and a processing algorithm can give precision to the actual location.

A method for measuring a property of a test object with an interferometer includes: a) providing calibration information relating a focus setting for the interferometer to a position of the test object relative to a reference surface of the interferometer; b) determining the position of the test object relative to the reference surface; and c) using the interferometer to collect interferometric images of the test object for use in measuring the property of the test object.

According to one aspect, the present description relates to a stabilized interferometric system comprising a light source (210) for emitting an initial beam (B.sub.0) of coherent light and a spatial light modulator (220) configured to receive at least a first part of said initial beam and input data (203), and configured to emit a spatially modulated beam (B.sub.0m) resulting from a spatial modulation of a parameter of said first part of said initial beam based on said input data. The stabilized interferometric system further comprises a scattering medium (230) configured to receive said spatially modulated beam and a detection unit (240) configured to acquire an interference pattern (IN.sub.0) in a first detection plane (241) at an output of said scattering material, wherein said interference pattern results from the interferences between randomly scattered optical paths taken by the spatially modulated beam through the scattering material. The stabilized interferometric system further comprises a control unit (250) configured to vary the frequency of the laser source in order to at least partially compensate a change in said interference pattern resulting from a change in at least one environmental parameter.

A device includes a first component, a second component having a reconfigurable distance from the first component, an optical element, an SMI sensor, and a processor. The optical element has a fixed relationship with respect to the first component, and has a known optical thickness between a first surface and a second surface of the optical element. The SMI sensor has a fixed relationship with respect to the second component, and has an electromagnetic radiation emission axis that intersects the first and second surfaces of the optical element. The processor is configured to identify disturbances in an SMI signal generated by the SMI sensor, relate the disturbances to the known optical thickness of the optical element, and to determine a distance between the first and second components using the SMI signal and the relationship of the disturbances to the known optical thickness of the optical element.

Provided is a method for calibrating an error of installation of an interferometer in a multi-axis laser displacement measurement system, including: adding one or more redundant interferometers in a laser interferometer displacement measurement system; then establishing displacement calculating equations containing installation error of the laser interferometer and obtaining redundant measurement information by continuously measuring displacement information of multiple points, wherein the number of the combined displacement calculating equations is equal to the number of unknown quantities; and further solving the equation set to obtain the installation error of the interferometer. With a redundant arrangement of the laser interferometer, self-calibration of the installation error thereof can be achieved. A problem of difficulty in calibration of the installation error of the multi-axis interferometer in industrial application can be solved without assistance of other displacement sensors with higher precision.