| 摘要 |
PURPOSE:To enable to perform monitoring, and to grasp the plasma condition accurately extending over a long period at a plasma etching device by a method wherein the thin film of an inorganic or an organic halogen compound not to react with active reaction chemical seeds in plasma is formed on the surface of an optical window. CONSTITUTION:High-frequency electric power is made as to be applied from a high-frequency electric power source 4 between electrodes 2, 3 in a chamber 1, plasma 5 containing active reaction chemical seeds such as fluorine ions, etc. is generated between the electrodes 2, 3 according to application of high-frequency electric power, and etching of an SiN4 film is generated. Detection of the condition of plasma 5 at this case is attained by detecting the emission spectrum of N2. Lights 7 of various wavelengths are taken out outside from an optical window 6 according to generation of plasma 5, while a spectrum (wavelength is 336nm) generated by N2 corresponding to the etched condition of the SiN4 film is made as to be separated and detected from the light 7 according to a photo detector 8. The amount of emission corresponding to the emission spectrum of N2 detected electrically is offered for display, etc., while the plasma condition is grasped according to the amount of emission thereof, and moreover, etching is monitored. |
