DRY ETCHING SYSTEM AND METHOD FOR DETECTING END POINT OF DRY ETCHING

PROBLEM TO BE SOLVED: To detect the end point of dry etching of a semiconductor film formed on a transparent substrate, by monitoring advance of dry etching from the back side of the transparent substrate. SOLUTION: The dry etching system 15 comprises upper and lower electrodes 2, 3 disposed oppositely in a reaction chamber 1, and a transparent substrate provided with a material being etched and mounted on the lower electrode 3, where plasma 8 is generated with high frequency power between the upper and lower electrodes 2, 3, in order to dry etch the material being etched. The dry etching system 15 further comprises members 5b, 5b for introducing plasma light generated in the reaction chamber 1 to the outside through openings 3a, 3a made in the etching material, the transparent substrate and the lower electrode 3, a detector 9 for detecting variation of the plasma light introduced by the members 5b, 5b, and a section 10 for determining the end point of dry etching, based on the detection results of the detector 9 and stopping high frequency power supply.