High-Speed and Fine Accuracy Inspection System by the Integration of the Phase Analysis of Laser and Visual Image Signal Processing

摘要

PURPOSE: A high-speed precision examination system using a combination of a laser phase shift analysis and a visible ray video signal analysis is provided to measure a pattern and a surface roughness of a thin film by scanning a laser beam to a panel and detecting the laser beam reflected on the panel. CONSTITUTION: A laser generator(1) generates a laser beam with a predetermined wavelength. A laser modulator(2) modulates or demodulates the laser beam outputted from the laser generator(1). A reference beam detector(92) detects a part of the modulated laser beam outputted from the laser modulator(2) as a reference beam. An optic system scans the modulated laser beam to a measuring object(71) loaded on a table. A reflective beam detector(91) detects the laser beam reflected by the measuring object(71). A data processing device(10) compares a detected signal of the reference beam detector(92) with a detected signal of the reflective beam detector(91) and determines a difference of pattern composition and a surface roughness of the measuring object by analyzing a frequency.