摘要:
A method for inspecting objects such as semiconductor wafers. A staging platform and an optical platform are arranged so that the object may be staged and its surface scanned by optical equipment situated on the optical platform. During the scanning process, the surface is illuminated with light of a plurality of wavelengths, each strobed at a predetermined rate so that multiple images may be collected using time and frequency multiplexing. The multiple images are stored in a database for analysis, which includes processing selected ones of the multiple images according to one or more algorithms. The defect-detection algorithms used for each object are determined by referenced to a predetermined or calculated defect detection protocol, then a defect mask is created for each pixel in the images that is suspected to be defective. The defect mask is then compared to threshold parameters to determine which if any of the suspected defects should be reported.
摘要:
A system and method for performing optical inspection of structures on the surface of a semiconductor wafer. The wafer surface is illuminated with a polychromatic light source. A multiple-charged couple-device (CCD) camera is positioned to capture light diffracted by the structures on the wafer surface at the first order of diffraction. The captured light is then separated into a plurality of component wavelengths which are directed onto the CCDs. A digital filter creates a plurality of digitized diffractive images of the wafer surface at different component wavelengths. The diffractive images may be integrated and analyzed to detect defects in the structures, or may be, analyzed individually. An image at a particular wavelength may be selected and analyzed by using the known grating pitch of the structures to calculate the wavelength.
摘要:
A method for inspecting objects such as semiconductor wafers. A staging platform and an optical platform are arranged so that the object may be staged and its surface scanned by optical equipment situated on the optical platform. During the scanning process, the surface is illuminated with light of a plurality of wavelengths, each strobed at a predetermined rate so that multiple images may be collected using time and frequency multiplexing. The multiple images are stored in a database for analysis, which includes processing selected ones of the multiple images according to one or more algorithms. The defect-detection algorithms used for each object are determined by referenced to a predetermined or calculated defect detection protocol, then a defect mask is created for each pixel in the images that is suspected to be defective. The defect mask is then compared to threshold parameters to determine which if any of the suspected defects should be reported.
摘要:
A method of collating and using captured semiconductor-wafer image data in an automated defect analysis. The method includes the steps of receiving image data and, if necessary, converting it to a digital format. Once the data is in pixel-by-pixel form, each pixel is assigned a slope value derived from the direction of the structure edge, if any, on which it lies. The pixel-slope data is then evaluated to determine whether a photo-resist anomaly is present. The method may also include evaluated an average pixel slope value for each inspected wafer. Dependant claims further define the invention to claim an inspection system for employing the method.