Study of Alternative Plasma Strip Techniques for Advanced Photoresist Removal

摘要

This paper reports on the investigation and development of two alternative plasma strip processes to meet the photoresist (PR) removal requirements of future technology nodes. Experimental results show that new plasma strip approaches not only have comparable crust breakthrough and removal capabilities as those of traditional O2/N2:H2 and fluorine-containing strip processes, but result in significantly lower silicon oxidation and hence the recess. In addition, an improved residue removal capability and very low metal (TiN and TaN) oxidation values have also been demonstrated. SIMS analyses of implanted silicon wafers processed with the new strip approaches have shown minimal dopant loss and profile changes. This work demonstrates that these novel plasma strip approaches are viable candidates for meeting the demanding wafer cleaning requirements of the 32nm technology node and beyond.