METHOD AND DEVICE FOR CONTROLLABLY REVEALING STRUCTURES BURIED IN OBJECTS SUCH AS WAFERS

摘要

According to the present invention, the structure 70a, 70b, 70c surrounded by the object 20, such as vias, in the region of the object 20, such as a wafer, is formed on the image sensor 22. Images for inspection, using optical imaging means 34, which can be generated by 73, 74, and illumination means 23, 27 for generating illumination beams 25, 30 and also illuminating the field of view with reflections. In the method, the spectral component corresponds to the properties of the object 20 so that the light of the beam 25, 30 has a first illumination beam 25, 30 through which the object 20 can pass. Obtaining a first image (73) of the object (20) by illuminating the object (20); The spectral component is adapted to the characteristics of the object 20 such that the light of the beam 25 30 has the second illumination beam 25, 30 that is reflected by the surface of the object 20. Obtaining a second image (74) of the object (20) by illuminating; And comparing the first and second images 73 and 74 to identify the structure 71a that appears in the first image 73 but does not appear in the second image 74. It relates to a video method and an apparatus.