Abstract: A sample treating method and apparatus adapted to treat a sample such as a semiconductor element substrate or the like and, particularly, a sample that must be etched and anticorrosion-treated. The adhered matters formed by the etching of the sample are removed from the sample sufficiently and easily when the etched sample is treated by utilizing the plasma of an anticorrosion gas that is capable of removing the adhered matters. There is required no wet-type anticorrosion treatment enabling the throughput to be improved in treating the samples that must be etched and anticorrosion-treated.

Abstract: This invention relates to a method and apparatus for monitoring etching. The monitor method comprises the steps of regulating a gas pressure inside a treating chamber, in which a sample is being etched by a dry etching process, to a pressure at which a emission line spectrum can be clarified, converting the gas whose pressure is regulated to plasma, and monitoring the etching state of the sample from the change of the intensity of the emission line spectrum with time.