By Karlsruhe Nano Micro Facility (KNMF)
Optical Nano-Metrology (Contact: Richard Thelen) Compared to using only AFM, we expand the application range with two optical metrology devices: a confocal scanning microscope and a vertical scanning interferometer. The confocal scanning microscope is best suited for surfaces with high texture, such as paper, crystalline, or porous surfaces. In contrast, the vertical scanning interferometer is ideal for smooth and thin layers or large areas with low z dimensions. While the lateral resolution of both optical metrology systems is limited to about 250 nm, the z resolution is approximately 2 nm for the confocal system and exceeds 0.5 nm for the vertical scanning interferometer when using phase shift imaging. These optical measurements are very fast. Both instruments support AFM measurements by providing valuable information about sample properties, helping to determine whether it makes sense to apply AFM. AFM is the ultimate 3D metrology technology but is applicable only if the sample meets high demands on flatness, roughness, and cleanliness. We can easily check these requirements with the optical instruments located in the same clean room.
