A novel anti-reflective structure with Al/SiO2 stack films for metal layerpatterning

In lithographic processing to define patterns on the high reflective substr ate, ARLs (anti-reflective layers) not only enable better line width contro l but also realize designs that were previously impossible to print. So far , several anti-reflective films such as TiN, SiOxNy:H, and organic films fo r the high reflective substrate have been studied. In this paper, we sugges t the novel anti-reflective structure for metal layer patterning, which is an Al (aluminium)/SiO2 stack structure. The reflectivity and resist absorpt ion rate are simulated for the I-line and ArF lithography. The simulated th ickness of ARL (Al) and ARL (SiO2) for zero reflectivity on the wavelength of 365 nm was 12.6 nm and 95.2 nm respectively, and on the 193 nm was 20.4 nm and 98.8 nm respectively. The process latitude according to the thicknes s variation of the deposited ARL (AI) and ARL (SiO2) films, and the results of the lithography experiment were discussed.