PERFORMANCE OF THE MODIFIED SUSS XRS 200 2M X-RAY STEPPER AT CXRL/

An XRS 200 model 2M X-ray stepper has been installed at the Center for X-ray Lithography. This paper describes the capability of the machine and its installation. Of greater interest is the performance the step per gives with respect to the dose control and the mask/wafer alignmen t. How robust a process is depends on the latitude of each process par ameter and the control tolerance accorded the machines and materials t hat affect each one. The dose repeatability and uniformity is determin ed by the optical elements in the beamline, the helium delivery system , and the accuracy of the scanning stage. Test results are reported fo r dose control using three separate methods. The scan speed is measure d using Suss supplied equipment and is verified separately by CXrL's o wn technique. The dose delivered is analysed by the response of radiac hromic film. Also important is the behavior and performance of the ALX -100 alignment system. The optical set-up is described as a model that includes the ALX hardware and illumination as well as the mask and wa fer. The signal and contrast from the mask and wafer are compared to d ata for several substrates. A figure of merit is discussed for determi ning which membranes will give the best overlay.