ALIGNER, METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE, SEMICONDUCTOR MANUFACTURING PLANT, AND METHOD OF MAINTAINING ALIGNER

摘要

PROBLEM TO BE SOLVED: To eliminate warm-up time and periodic maintenance for oxygen concentration measurement, to reduce power dissipation for oxygen concentration measurement, and to prevent bad influence due to the heat generated by oxygen concentration measuring means. SOLUTION: In an aligner having oxygen concentration measuring means for measuring the oxygen concentration in the optical path for the exposing light, the oxygen concentration measuring means 2-6 measure the oxygen concentration by measuring the drop of the exposing light 7 by oxygen.