Patent ID: 8198195

Claim:
A plasma-processing method comprising: generating a plasma by supplying gases for plasma excitation including a mixed gas of argon and at least one of xenon and krypton as a rare gas through an upper shower plate, said rare gas having a composition ratio of the at least one of xenon and krypton to the mixed gas of 20% or more by volume for plasma excitation; and supplying a reactive gas from a lower shower plate for processing a workpiece by the use of said plasma, wherein a pressure of the mixed gas is controlled to be 2.66 to 5.33 Pa, and said processing includes one selected from the group consisting of: (a) oxidizing of at least a portion of a surface of said workpiece; (b) nitriding of at least a portion of a surface of said workpiece; (c) oxynitriding of at least a portion of a surface of said workpiece; and (d) film forming on at least a portion of a surface of said workpiece.