Alternative technology for double patterning process simplification

In this paper, we will present experimental results on sub-40nm node patterning of DRAM and some technical issues for capping freezing in simplified double patterning lithography. Lithography resolution limit of single pattern is 40nm in ArF immersion process. For sub-40nm patterning, we have to use double patterning lithography or EUV process. But, double patterning lithography process is very complicated and expensive solution. And EUV volume production technology will be not ready until 2012. Therefore, we have tried a simplified double patterning lithography.