Automated nanoscale AFM measurements using a-priori-knowledge

摘要

The Nanometer-Coordinate-Measuring-Machine (NCMM) has been developed for comparatively fast large area scans with high resolution for measuring critical dimensions. The system combines a metrological atomic force microscope (AFM) with a precise positioning system. The sample is moved under the probe system via the positioning system achieving a scan range of 25 × 25 × 5 mm with a resolution of 0.1 nm. A concept for critical dimension measurement using a-priori-knowledge is implemented. A-priori-knowledge is generated through measurements with a white light interferometer and the use of CAD data. Dimensional markup language (DML) is used as a transfer and target format for a-priori-knowledge and measurement data. Using a-priori-knowledge and template matching algorithms combined with the optical microscope of the NCMM, the region of interest can be identified automatically. In the next step an automatic measurement of the part coordinate system and the measurement elements with the AFM sensor of the NCMM is performed. Automatic measurement involves intelligent measurement strategies, which are adapted to specific geometries of the measurement features to reduce measurement time and uncertainty.