248nm Process Is Capable for sub 0.09 um Groundrules

Abstract

While the mainstream wafer production is at 0.065 and 0.045 um with 300 mm diameter wafers with ArF exposure tools systems, an idea to explore production feasibility under groundrules smaller than 0.09 um while maintain the cost advantages in KrF exposure tools systems becomes more and more popular and important to all companies including 300mm/200mm FAB. But the k1 factor for sub 0.09um with current popular KrF exposure tools will be about 0.31, which has the same level of complexity in optical proximity correction compared to 0.045 um at 0.93 NA with 193 nm exposure tools. Several RET (Resolution Enhancement Technology) techniques have been proposed for low k1 case and some good results have been achieved. However, each RET techniques has their own merits and demerits. It is still attractive to find out a solution with current KrF exposure tools, popular illumination settings and cost effective masks. In this paper, we will introduce our study for sub 0.09 um design rule with maximum 0.82NA KrF scanner tools. No special RET techniques are used and acceptable DOF, EL, MEEF, LWR and CD proximity are achieved. A novel photoresist optimization solution is both discussed.