METHOD FOR DETECTING LEAKAGE OF OUTER GAS INTO VACUUM CHAMBER

摘要

A method for detecting inflow of the outside air of a vacuum chamber is provided to measure performance of outside air blocking during processing by performing a light detection of gas existed in the vacuum chamber. Process gas is charged into a vacuum chamber(S10). Gas existed in the vacuum chamber is light-detected to measure intensity of a wavelength where the process gas and the outside air are included(S20,S30). A ratio of the outside air to the process gas is calculated based on the measured intensity of the wavelength(S40). Background level intensity of each wavelength where the process gas and the outside air are included is calculated by measuring intensity of a neighboring wavelength. Net wavelength intensity of each wavelength where the process gas and the outside air are included is calculated by subtracting the background level intensity therefrom. When the ratio is greater than a limited value, an alarm is sent out(S50,S60).