Abstract: In one example, a workpiece support structure of a plasma treatment chamber has upper and lower ends, and first and second support members that extend between the upper and lower ends. The support members are electrically isolated from one another and offset from one another along a horizontal direction so as to define a cavity therebetween. The first and second support members support electrodes within the cavity such that (1) the electrodes are offset from one another along the vertical direction, (2) the electrodes extend between the first and second support members along the first horizontal direction, (3) a first set of the electrodes are electrically coupled to the first support member and electrically isolated from the second support member, and (4) a second set of the electrodes, different from the first set, are electrically coupled to the second support member and electrically isolated from the first support member.