Patent ID: 7481230

Claim:
A plasma processing method having a first and a second plasma processing step carried out in a single chamber, wherein deposits are substantially accumulated in the chamber during the first plasma processing step, the method comprising the steps of: dry cleaning an inside of the chamber by using a dummy substrate between the first and the second plasma processing steps, wherein the dry cleaning step is performed by supplying into the chamber a deposit removing gas for removing the deposits produced in the chamber during the first plasma processing step and supplying a dummy substrate etching gas that etches the dummy substrate and stabilizes an etching rate of the second plasma processing step, which is carried out right after the dry cleaning step, wherein the second plasma processing step includes a plasma etching performed without producing deposits in the chamber, and wherein a first CF-based gas is supplied in the first plasma processing step, and a second CF-based gas comprising CF 4 , O 2 , and Ar is supplied in the second plasma processing step, and the first CF-based gas has a different composition from the second CF-based gas such that a fluorine/carbon (F/C) ratio of the first CF-based gas is smaller than that of the second CF-based gas.