Multilayer bottom antireflective coatings for high numerical aperture and modified illumination exposure systems

In the recent ITRS roadmap, ArF and F/sub 2/ excimer laser lithographies combining with resolution enhancement techniques would lead IC technologies to generations of 90 nm and 65 nm, respectively. For increasing resolution of optical lithography, expose systems with high numerical aperture (NA) are essential. The efficiency of the conventional single-layer BARC structure will degrade as the incident angle increased. It is due to the reflectance at resist/BARC interface increases in the large incident-angle regime. Here we demonstrate a multilayer bottom antireflective coating (BARC) layer for high-NA exposure systems in ArF and F/sub 2/ lithographies.