Application of attenuated phase-shifting masks to sub-130-nm lithography

In this paper, the performance of 6% and 18% attenuated phase-shifting masks (PSM) are investigated to assess their capabilities of printing 0.12μm and 0.10μm polysilicon gates, using a 248nm scanner with a high NA of 0.68. The effect of off-axis illumination on process enhancement is also investigated. Simulations were done using PROLITH/3D Version 6.1.2. Experimentation was carried out using test masks with various line pitches. The effect of optical proximity correction (OPC) to enhance the overlapping process windows for 0.12μm and 0.10μm was also studied.