For very smooth wafer surfaces, interferometric imaging can acquire surface textures with a resolution down to 0.1 nm. The entire scan took less than 3 seconds.
Contrast methods: Images of part of a wafer: a) quick surface overview followed by detection of b) particles with brightfield, c) micro-scratches with darkfield, and d) defects on transparent films with differential interference contrast (DIC). Imaging with each illumination mode is completed in seconds.
Our imaging systems allow you to visualize difficult-to-image wafer features more easily to achieve more efficient and accurate wafer inspection and quality control. The image quality in terms of contrast and level of detail easily seen depends strongly on the lighting and optics used.
So choosing the appropriate lighting contrast method and using maximally corrected, high performance optics is imperative. Different wafer and device features, e.g., coatings, contamination, scratches, and defects, are more enhanced with one lighting contrast method compared to another.
High Performance Optics
High quality optics can make your wafer and semiconductor device inspection work more efficient, because you will see the fine details clearly with less effort. Leica Microsystems’ imaging systems use top-performing, award-winning optics which produce distortion free images. Optics can suffer from 2 types of aberration which require correction:
- monochromatic (independent of the light’s wavelength [color]), such as astigmatism, coma, and field curvature
- chromatic (dependent on the light’s wavelength).
Our optical designers and engineers provide optics which enable you to inspect wafers and devices with optimal contrast and resolution.