Contactless measurement of critical dimensions, forms and quality
Laser light has multiple unique physical properties that can be used for metrology applications: An extremely defined wavelength and frequency, a perfect focussability (TEM00), high or low optical coherence (phase quality) and cw/pulsed operation mode (down to fs pulses). Each of those light properties can be used in metrology to determine critical dimensions, distances, angles, shapes, internal structures, layer thickness, chemical analysis etc. of samples in off-line or in-line inspection.
Since laser metrology works contactless, neither the sample nor the metrology tools are influenced or deteriorated during the measurement process. Also the laser can operate remotely from the area of interest, providing the necessary information from long distance, in extreme cold or hot environment or in very confined geometry. Nowadays laser metrology is commonly used in almost all industrial manufacturing processes, using lasers from the very deep Ultraviolett up to far Infrared or even Terahertz wavelengths.