Si etching residual removal method for device of very fine structure

PURPOSE: To realize a plasma etching process used for manufacturing the device of very fine structure, by reacting a wafer under the designated condition in a plasma produced from a gas mixture including fluorine. CONSTITUTION: A parallel plate reaction vessel is made up of an etching vessel 10 consisting of a cylindrical nonconductive part 12 and two conductive plates 14, 16. A wafer 20 is placed on a holder 18 by a cover plate 24 with a window penetrated therefrom and supported thereto. An end plate 14 is connected to a position of a reference potential like ground. The plate 14 acts like an anode of the reaction vessel. The sample holder 18 configures a driven cathode of the reaction vessel. A proper gas compound including fluorine is introduced in the vessel 10, and an electric field is applied between the anode 14 and the cathode 18 to allow a reaction plasma to be generated in the vessel 10. The plasma generated therein has a uniform dark space just close to the surface of the sample to be etched. A volatile product formed on the surface of the sample in the etching process is discharged from the vessel by a pump system 42. COPYRIGHT: (C)1991,JPO