Novel embedded barrier layer materials for ArF non-topcoat immersion applications

With the decrease in pitch in the line/space patterning, micro-bridge defects have become the major defect in the immersion applications. As a result, reducing micro-bridge defect count is one of the key tasks for mass production of semiconductor devices using immersion lithography for both topcoat and non-topcoat processes. In this paper, we focus on the non-topcoat approach particularly the embedded barrier layer (EBL) technology. The advanced EBL materials discussed in this paper have demonstrated to be able to reduce total defect including micro-bridge defect count to the same level as that of a topcoat process. It was found that the developer solubility of the EBL materials in both bright and dark fields and the contrast of the EBL materials play important roles for reducing overall defectivity.