DEVICE AND METHOD FOR DETECTING END POINT OF CLEANING

摘要

PURPOSE: To provide a method for detecting the end point of cleaning which can detect the end point of the cleaning treatment to remove the deposits on the inner wall or the like of a reaction chamber with excellent accuracy. CONSTITUTION: A reaction chamber 1 containing cluster clouds formed through the reaction of the reaction product gas generated by the reaction between a part of the adhered stuff and the cleaning gas during the cleaning treatment, in the vapor phase, and separation particles which are a part of the adhered stuff separated from an inner wall due to the reduction in adhesion resulting from the formation of the cluster clouds (the particle size of the separation particles is larger than the particles size of the cluster clouds) is irradiated with laser beam 4, the cluster clouds and the separation particles 2 are measured by the laser beam scattering method, and the cleaning end point is judged as the time point of time when no deposits are present, and any cluster clouds or separation particles are observed.