The state-of-the-art for mask making continues to be driven by 1x x-ray masks. The IBM EL4+ e-beam mask writer at the Advanced Mask Facility in Burlington, Vermont, was originally designed for 0.35 mu m ground rules (GRs) direct write at 50 kV, but delivered at 75 kV operation to achieve 0.25 mu m GR performance for 1x mask making. Over the next 2 years, with optimization and improvements in each of the subsystems, its performance was enhanced beyond the 0.18 mu m GR requirements. It is clear, however, that for 0.13 and 0.1 mu m GR mask manufacturing, a new tool is required. It has also become apparent that because of the very high development and tool build costs, and small number of required x-ray mask makers, the same technology must be applicable for chrome on glass (COG) mask making. Based on the experience with EL4+, IBM is designing an EL5 tool which will provide the 0.13/0.1 mu m GR performance for 1x, and easily convert to 4x COG exposure for 9 in. glass as well as 300 mm wafer direct write operation. As with previous IBM EL series e-beam systems, it is anticipated that EL5 performance will be extendable beyond 0.1 mu m GR.