Variable depth edge ring for etch uniformity control

A method of operating a substrate support includes arranging a substrate on an inner portion of the substrate support and calculating a desired pocket depth of the substrate support using data indicative of a relationship between the desired pocket depth and at least one process parameter. The desired pocket depth corresponds to a desired distance between an upper surface of an edge ring surrounding the inner portion and an upper surface of the substrate. The method further includes selectively controlling, based on the desired pocket depth as calculated, an actuator to raise and lower at least one of the edge ring and the inner portion to adjust the distance between the upper surface of the edge ring and the upper surface of the substrate.