A method for detecting an internal crack in a wafer includes a first image recording step of applying near infrared light having a transmission wavelength to a reference wafer having the same configuration as a target wafer to be subjected to the detection of the internal crack, thereby obtaining a first image of the reference wafer having no internal crack and then recording the first image, a processing step of processing the target wafer, a second image recording step of applying the near infrared light to the target wafer, thereby obtaining a second image of the processed target wafer and then recording the second image, and an internal crack detecting step of removing the same image information between the first image and the second image from the second image to obtain a residual image, thereby detecting the residual image as the internal crack in the target wafer.

The present disclosure is directed to a method for designing an aperture in a mask for inspecting a wafer. The method includes the steps of scanning a collection plane of the wafer at a plurality of points and collecting data for at least a part of the wafer. The method also includes the step of mapping the data. A further step of the method includes configuring the aperture based on the mapped data.

A height detection apparatus successively changes the brightness of white light from a first level to a second level in accordance with a position of a Z stage and captures an image of interference light while moving a two-beam interference objective lens relative to a paste film in an optical axis direction, detects, as a focus position, a position of the Z stage where the intensity of interference light is highest in a period during which the brightness of white light is set to the first or second level, for each pixel of the captured image, and obtains the height of the paste film based on a detection result.

An inspection method uses a charged particle microscope to observe a sample and view a defect site or a circuit pattern. A plurality of images is detected by a plurality of detectors and a mixed image is generated by automatically adjusting and mixing weighting factors required when the plurality of images are synthesized with each other. The sample is irradiated and scanned with a charged particle beam so that the plurality of detectors arranged at different positions from the sample detects a secondary electron or a reflected electron generated from the sample. The mixed image is generated by mixing the plurality of images of the sample with each other for each of the plurality of detectors, which are obtained by causing each of the plurality of detectors arranged at the different positions to detect the secondary electron or the reflected electron. The generated mixed image is displayed on a screen.

Predictive modeling based focus error prediction method and system are disclosed. The method includes obtaining wafer geometry measurements of a plurality of training wafers and grouping the plurality of training wafers to provide at least one training group based on relative homogeneity of wafer geometry measurements among the plurality of training wafers. For each particular training group of the at least one training group, a predictive model is develop utilizing non-linear predictive modeling. The predictive model establishes correlations between wafer geometry parameters and focus error measurements obtained for each wafer within that particular training group, and the predictive model can be utilized to provide focus error prediction for an incoming wafer belonging to that particular training group.

Implementations disclosed describe, among other things, a system and a method of scanning a substrate with a beam of light and detecting for each of a set of locations of the substrate, a respective one of a set of intensity values associated with a beam of light reflected from (or transmitted through) the substrate. The detected intensity values are used to determine a profile of a thickness of the substrate.

A measurement apparatus for measuring a thickness of a semiconductor wafer includes: an optical system configured to perpendicularly irradiate a sample wafer and a reference wafer with light, and receive interference signals of the light reflected on front and back surfaces of the respective wafers; a signal processor configured to perform frequency analysis of the interference signals received by the optical system to obtain peak positions of a point spread function of the respective wafers; and a calculator configured to calculate a thickness tsample of the sample wafer based on the peak position x of the sample wafer and the peak position y of the reference wafer obtained by the signal processor, and a thickness treference of the reference wafer.

A wafer thickness measurement device of the present invention obtains, based on: first and second interferometer reference measurement results obtained by measuring, with an A-surface optical interferometer and a B-surface optical interferometer, a reference measurement point on a reference piece having the reference measurement point at which the reference piece has a known thickness; first and second distance meter reference measurement results obtained by measuring the reference measurement point with an A-surface distance meter and a B-surface distance meter; first and second interferometer measurement results obtained by measuring a measurement point of the wafer with the A-surface optical interferometer and the B-surface optical interferometer; and first and second distance meter measurement results obtained by measuring the measurement point with the A-surface distance meter and the B-surface distance meter, and obtains a thickness, of the wafer, at the measurement point.