Wafer Edge Protection and Efficiency Using Inert Gas and Ring

A method for processing a substrate, comprising:

• placing a substrate on a substrate support within a process chamber;
• flowing an edge-exclusion gas through a gap defined between a process ring and the substrate, wherein the gap is between about 0.1 mm and about 1.0 mm;
• and
• confining the edge-exclusion gas flow exiting the gap from flowing radially outward over a distance above a top surface of the substrate, wherein the distance ranges from about 2.2 mm to about 5.2 mm and the edge-exclusion gas flow rate ranges from about 5 sccm to about 15 sccm.

A method for processing a substrate, comprising:

• supplying a gas mixture into a process chamber having a substrate disposed therein, wherein the substrate is disposed over a substrate support;
• generating a plasma in the process chamber from the gas mixture supplied in the process chamber;
• and
• flowing an edge-exclusion gas through a gap defined between the substrate and a process ring disposed on the substrate support, wherein the ring confines the edge-exclusion gas from flowing radially outward over a distance of at least about 2.2 mm above a top surface of the substrate.