With the advent of 193 nm systems processing 300 mm wafers, the production lithography cell is about to undergo a technology shift. The mechanism for delivering the beam from the light source to the illumination system, here referred to as a Beam Delivery Unit (BDU), must change to meet the challenges imposed by this shift. To support these changes, Cymer is developing a BDU that will guarantee a stable beam at the scanner entrance during exposure. The beam stabilization control system has been implemented in a test BDU. We shall present results from experiments that demonstrate our ability to significantly improve short and long term “Beam Stability”.