Semiconductor device fabrication equipment performs a PEOX (physical enhanced oxidation) process, and includes a remote plasma generator for cleaning a process chamber of the equipment. After a PEOX process has been preformed, a purging gas is supplied into the process chamber to purge the process chamber, and the remote plasma generator produces plasma using a first cleaning gas. Accordingly, a reactor of the remote plasma generator is cleaned by the first cleaning gas plasma. Subsequently, the purging gas is supplied to purge the process chamber, and the remote plasma generator produces plasma using a second cleaning gas to remove the first cleaning gas plasma from the remote plasma generator and the process chamber. Finally, full flush operations are performed to remove any gases remaining in the process chamber.