Patent ID: 7695763

Claim:
A substrate processing method for performing a nitriding process on a target substrate accommodated in a process chamber, the method comprising: performing a cleaning cycle a plurality of times within the process chamber in which the target substrate is not present, wherein the cleaning cycle includes, in an alternating manner, a first period of cleaning the process chamber by supplying a first mixture gas consisting of oxygen gas and argon gas into the process chamber and generating first plasma of the first mixture gas, and a second period of cleaning the process chamber by supplying a second mixture gas consisting of nitrogen gas and argon gas into the process chamber and generating second plasma of the second mixture gas; after the performing, seasoning the process chamber in which the target substrate is not present by supplying the second mixture gas into the process chamber and generating plasma of the second mixture gas; and after the seasoning, loading the target substrate into the process chamber and performing the nitriding process on the target substrate, wherein the substrate processing method comprises no period of cleaning the process chamber by use of a fluorine-containing compound inside the cleaning cycle or between the cleaning cycle and the nitriding process.