Carrier ring wall for reduction of back-diffusion of reactive species and suppression of local parasitic plasma ignition

摘要

A carrier ring configured to support a substrate during transport to or from a pedestal of a process tool and surrounding the substrate during processing is defined by, an inner annular portion having a first thickness, the inner annular portion defined to be adjacent a substrate support region of the pedestal; a middle annular portion surrounding the inner annular portion, the middle annular portion having a second thickness greater than the first thickness, such that a transition from a top surface of the inner annular portion to a top surface of the middle annular portion defines a first step; an outer annular portion surrounding the middle annular portion, the outer annular portion having a third thickness greater than the second thickness, such that a transition from the top surface of the middle annular portion to a top surface of the outer annular portion defines a second step.