BARC OPEN IN FINFET TECHNOLOGY NODE

Single PR (photoresist) photo works well in implantation process for planar transistors, however, it suffers severe PR residue issue in FinFET technology node due to the three dimensional fin/gate structure and large wafer surface topography. New integration scheme with BARC (Bottom Anti-Reflective Coating) coating/etching was developed to solve this problem. In this work, BARC etching process was compared on two different types of commercial etcher. Key factors which influenced the BARC etching uniformity, remaining PR thickness and BARC profile were discussed. Finally, we delivered a BARC etching process with desired physical profile and improved device performance.