No abstract

The attenuated (or half-tone) phase shift mask (APSM) has been used to delineate O.22prn contact hole structures for O.l8m technology. Using a scanner with a high NA of 0.68, this is equivalent to a k1 value of 0.60. As device shrinks down to O.l3jim technology, O.16tm contact holes are to be printed with sufficient process latitudes. Using the existing high NA scanner, the k1 value is a low 0.44. Simulations were done using PROLITHI3D software, and the results show better performance for isolated holes. Higher mask transmissions are required to improve the aerial image ofthe dense holes. Experimentation was conducted to print O.16xm contact holes using moderate and low r settings. 6% APSM was used with O.l6jtm, O.l8.tm and O.2Om contact hole patterns biased by O.O4im, O.O6tm and O.O8tm. Impact ofthese parameters on mask error enhancement factor (MEEF) were discussed.

No abstract

In this paper, the performance of 6% and 18% attenuated phase-shifting masks (PSM) are investigated to assess their capabilities of printing O.12tm and O.lOjim 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 PROLITHI3D 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. 12pm and O.1Otm was also studied.