results above show that there having center and edge gas feeds provide additional process knobs to use for selecting a most suitable bevel edge etching processes in addition adding a tuning gas such as n 2 ar or he or a mixture of multiple tuning gases can change the etching profile at the bevel edge of substrate further total gas flow and gap distance between the gas delivery plate and substrate surface can also affects etching profiles in addition as shown in the results and description above process gas type can have an impact on the etching profiles and interacts with the tuning gas the various factors mentioned above either change the plasma composition or changes characteristics at the bevel edge the changes affect the bevel edge etching profiles fig4 shows an exemplary process flow 400 of generating a bevel edge etching plasma by feeding process gas from edge gas feed s and feeding a tuning gas from center gas feed s to a process chamber at step 401 a substrate is place on a substrate support in a bevel edge etch plasma chamber at step 402 process gas es is fed to either an edge gas feed s or a center gas feed s in the processing chamber at an optional process step 403 a tuning gas es is fed to either an edge gas feed s or a center gas feed s in the processing chamber at step 404 an etching plasma is generated near the bevel edge of the substrate by powering either a top edge electrode or a bottom edge electrode if the top edge electrode is powered the bottom edge electrode is grounded if the bottom edge electrode is powered the top edge electrode is grounded at step 405 the thin film at the bevel.