Evaluation of different metal preclean conditions for MOL for 2nm and beyond

Abstract

We report the results from evaluating different metal preclean conditions for MOL applications for 2nm and beyond. Two different chambers were evaluated for removal of metal interfacial oxide prior to MOL metal liner deposition. Different blanket oxide etch experiments were conducted with heated H2 plasma and H2 plasma combined with Ar sputter removal (2-in-1 process) to understand etch removal, uniformity. Further electrical performance on MOL test structure was done to evaluate which preclean process showed superior electrical yield.