A fixture, for example, comprised in a semiconductor processing system, includes a standoff arranged for fixation relative to a reaction chamber of a semiconductor processing system. A slide member is slidably supported by the standoff and is translatable along a carrying axis extending into the reaction chamber. A male threaded member depends from the slide member and is rotatable about a seating axis that is angled relative to the carrying axis. A paddle member depends from the male threaded member, defines along the carrying axis, is fixed relative to slide member along the carrying axis to carry a component of a process kit into the reaction chamber using translation of the slide member, and is free relative to the slide member along the seating axis to seat the process kit component within the reaction chamber using rotation of the male threaded member.