Patent ID: 6954560
Filing Date: 2005-10-11
Classification: G01N

Abstract:
1. A method for determining concentration of one or more organic additive species in a sample metal plating solution, comprising the steps of providing an optical waveguide having a refraction index that is higher than that of the sample metal plating solution and placing said optical waveguide adjacent to the metal plating solution to form an interface between said optical waveguide and said metal plating solution, providing infrared light so that the infrared light propagates from the optical waveguide to said sample metal plating solution and is reflected back into said optical waveguide by said interface thereby effectuating attenuated total reflection of the infrared light in said optical waveguide, measuring attenuation of the infrared light, and determining concentration of said one or more organic additive species in said metal plating solution, based on the measured attenuation of the infrared light.