概要（Overview）

The PAS 5000/50 stepper by ASM Lithography has a 0.48 NA i-line lens with a 15x15 mm field and 0.5 um resolution. It boasts an enhanced overlay performance exceeding 125 nm with 99.7% accuracy. Using a dual through-the-lens alignment system, it negates the need for baseline references and send-ahead wafers. The system is unaffected by alignment mark variations, commonly seen on layers like grainy aluminum. Optimized illumination ensures high throughput and CD control for 0.5 um production. With a notable "etendu", it provides intense wafer plane illumination. Its precision is evident with a three-sigma CD repeatability of 0.03 um for 0.5 um features.