Method for controlling gas flow in process chamber for e.g. surface processing, in semiconductor industry, involves actively controlling mass flow controller in-situ based on concentration measurement of molecules, atoms, radicals and ions

摘要

The method involves actively controlling a mass flow controller (MFC) (7) in-situ based on concentration measurement of molecules, atoms, radicals and ions by methods of infrared absorption spectroscopy. The concentration measurement in a process chamber takes place on-line and in-situ. Radiation sources (4) for the infrared absorption spectroscopy are laser such as semiconductor laser, quantum cascade laser or interband cascade laser. The measurement takes place in plasma that is utilized for a dry etching process.