Abstract: In some embodiments, a method for etching features into a substrate may include exposing a substrate having a photoresist layer disposed atop the substrate to a first process gas to form a polymer containing layer atop sidewalls and a bottom of a feature formed in the photoresist layer, wherein the first process gas is selectively provided to a first area of the substrate via a first set of gas nozzles disposed within a process chamber and; exposing the substrate to a second process gas having substantially no oxygen to etch the feature into the substrate, wherein the second process gas is selectively provided to a second area of the substrate via a second set of gas nozzles disposed in the process chamber.

Abstract: Embodiments of the present disclosure generally provide apparatus and methods for improving process result near the edge region of a substrate being processed. One embodiment of the present disclosure provides a cover ring for improving process uniformity. The cover ring includes a ring shaped body, and an extended lip extending radially inwards from the ring shaped body. An inner edge of the extended lip forms a central opening to expose a processing region on a substrate being processed, and a width of the extended lip is between about 15% to about 20% of a radius of the central opening.