A plasma processing chamber includes a substrate support having a top surface defined to support a substrate in a substantially horizontal orientation within the chamber. The plasma processing chamber also includes a number of telescopic members disposed within the chamber outside a periphery of the substrate support. The number of telescopic members are also disposed in a concentric manner with regard to a center of the top surface of the substrate support. Each of the number of telescopic members is defined to be independently moved in a substantially vertical direction so as to enable adjustment of an open volume above the top surface of the substrate support, and thereby enable adjustment of a plasma condition within the open volume above the top surface of the substrate support.