Patent ID: 7875322

Claim:
A plasma processing method, comprising: supplying a process gas into a process chamber of a plasma processing apparatus, which accommodates a target object including a silicon surface; supplying electromagnetic waves into the process chamber to generate plasma of the process gas; and oxidizing the silicon surface by action of the plasma to form a silicon oxide film on the silicon surface, wherein the process gas consists essentially of Ar gas, H 2 gas, and O 2 gas with a flow rate of the Ar gas set within a range of 250 to 1000 mL/min, a flow rate of the H 2 gas set within a range of 1 to 20 mL/min, and a flow rate of the O 2 gas set within a range of 1 to 20 mL/min, wherein the oxidizing the silicon surface is performed under a process temperature of 300 to 800° C. and a process pressure of 66.7 to 266.6 Pa, wherein the electromagnetic waves are pulsated electromagnetic waves with a pulse-on-time of 10 to 100 μs, a pulse frequency of 1 to 100 kHz, and a duty ratio of 50 to 90%, so as to attain a state where a light-emission intensity of OH radicals in the plasma generated by the pulsated electromagnetic waves in an ultraviolet region, at 310 nm, is equal to or lower than 50% of a corresponding light-emission intensity of plasma generated by continuous electromagnetic waves, and wherein a silicon oxidation rate of the plasma generated by the pulsated electromagnetic waves is equal to or higher than 55% of a silicon oxidation rate of the plasma generated by the continuous electromagnetic waves.