Abstract: A method of and an apparatus for monitoring etching by-products, capable of detecting and analyzing laser induced fluorescent light generated upon irradiating laser beams onto a by-product formed in the etching process. The method includes the steps of: selecting an excited electron level capable of being borne by molecules or radicals of the by-product; irradiating onto the by-product a laser beam with energy of a wavelength corresponding to the selected excited electron level; optionally exciting the molecules or radicals of the by-product by the irradiated laser beam, thereby forming a primary excited state of the by-product; detecting a laser induced fluorescent light emitted from the by-product during the transition of the by-product from the primary excited state to a secondary excited state which exhibits an energy level lower than the primary excited state; and analyzing the detected laser induced fluorescent light.

Abstract: A method of and an apparatus for monitoring etching by-products, capable of detecting and analyzing laser induced fluorescent light generated upon irradiating laser beams onto a by-product formed in the etching process. The method includes the steps of: selecting an excited electron level capable of being borne by molecules or radicals of the by-product; irradiating onto the by-product a laser beam with energy of a wavelength corresponding to the selected excited electron level; optionally exciting the molecules or radicals of the by-product by the irradiated laser beam, thereby forming a primary excited state of the by-product; detecting a laser induced fluorescent light emitted from the by-product during the transition of the by-product from the primary excited state to a secondary excited state which exhibits an energy level lower than the primary excited state; and analyzing the detected laser induced fluorescent light.