Diluted low dielectric constant materials as bottom antireflective coating layers for both KrF and ArF lithography

For reduction interconnect signal delay, low dielectric constant (K) materials are being introduced to replace conventional dielectrics in next generation IC technologies. In the advanced lithography processes, a bottom antireflective coating (BARC) layer for patterning low-K materials is essential. Nitride-based (silicon nitride, silicon oxynitride) films have been demonstrated to have suitable optical characteristics for both KrF and ArF lithography BARC applications. However, dielectric constants of nitride films are about 4/spl sim/8. Therefore, the nitride films should be removed after pattering low-K materials. Here we demonstrate low-K materials for both KrF and ArF lithography BARC applications. The antireflective layer is composed of diluted low-K materials, such as BCB, FLARE, and SiLK.