Patent ID: 6506341
Filing Date: 2003-01-14
Classification: B24B,G01N,H01L,Y10T

Abstract:
An apparatus for performing a chemical-mechanical polishing process including removing a target film overlying a stopping film and for providing real-time control of the process by detecting the presence of a chemical in a gaseous state to yield a process endpoint signal, the chemical being selectively generated during the polishing process in a slurry as a reaction product with one of the stopping film and the target film, the apparatus comprising:a collector for collecting the slurry used in the chemical-mechanical polishing process, the slurry having the chemical dissolved therein; a gas extractor for extracting the chemical as a gas from the slurry; a catalytic converter for converting the chemical to a different chemical product, said catalytic converter having a heater for heating the converter to about 800Â° C. to perform the converting and having at least one input and at least one output, wherein the chemical to be detected is an input of the catalytic converter; a gas generator for generating a reactive gas; a reaction chamber for producing an excited species in the chemical product by a reaction with the reactive gas, the reaction chamber having at least one input and at least one output, wherein the chemical product is an output of the catalytic converter and is an input of the reaction chamber, and a pressure in the reaction chamber is maintained sufficiently low to substantially avoid collisional deactivation of the excited species, so as to permit real-time detection of the chemical; a light sensor for monitoring a level of light emitted from the excited species as the target film is removed, said light sensor having at least one input and at least one output, wherein a light signal from the excited species is an output of the reaction chamber and is an input of the light sensor, and an output of the light sensor corresponds to the real-time detection of the chemical, so that the output of the light sensor is the process endpoint signal; and a controller for providing real-time control of the chemical-mechanical polishing process, the output of the light sensor being an input of said controller.