To realize high productivity at the 100 nm node, ASML developed the TWINSCANTM AT:1100B. This dual stage 193 nm lithography system combines high throughput TWINSCANTM technology for 300 nm wafers, excellent dynamical performance, and low aberration 0.75 NA StarlithTM1100 projection optics. The system is equipped with a 20 W 4 kHz ArF laser and the AERIALTM II illuminator, enabling high intensity off axis and multi-pole QUASARTM illumination. Important process control requirements for the 100 nm technology node are CD variation across the chip and across the wafer. Full wafer leveling, including dies on the edge of the wafer, and CD uniformity performance on 300 mm wafers with and without topology are presented, showing full wafer CD uniformity numbers as low as 6.3 nm 3(sigma) for 100 nm isolated lines with assisting features. Imaging performance of dense, fully isolated lines, plus dense and isolated contact holes is shown. Also printing of critical customer structures is discussed. With these results it is demonstrated that the TWINSCANTM AT:1100B 300 mm ArF Step & Scan system meets the requirements for the 100 nm node.