Patent ID: 7928018

Claim:
A plasma processing method in which plasma is generated by the use of a plasma excitation gas and process gas is introduced into said plasma to thereby process an object to be processed, the method comprising: introducing said plasma excitation gas into a process chamber from an upper shower plate; generating said plasma under said upper shower plate; causing said plasma to pass through a lower shower plate provided under said upper shower plate so as to reach said object to be processed; and introducing said nitrous oxide gas, as said process gas, from said lower shower plate into the plasma whose electron temperature is less than binding energy 2.24 eV between a nitrogen molecule and an oxygen atom in said nitrous oxide, said nitrous oxide gas being introduced into the plasma under said lower shower plate, wherein said nitrous oxide gas is provided to said lower shower plate from a gas discharge tube provided at only one end of said lower shower plate, to thereby be discharged through respective openings of said lower shower plate into the process chamber.