Defects reduction at BEOL interconnect within 300mm manufacturing environment

Abstract

Process yield is a critical factor for a success of 300mm manufacturing. Typically, higher yield corresponds to lower defect counts within the respective processing steps (lithography, etch, plating, and CMP). Within BEOL lithographic processes, there are issues of defects within same lithographic technology and there are concerns of defects between the generation of lithographic technologies, for example, immersion, 193nm "dry", and DUV (248nm). In order to have an effective defect reduction strategy, defects have to be monitored, identified, and analyzed for points of origins. In this paper, we explore three areas of interests in the BEOL: 1) defects occur between different processing steps, specifically, after Immersion Lithography, after Reactive Ion Etch (RIE), and after Chemical Mechanical Polish (CMP), 2) defects after CMP between lithographic technologies (Immersion, Dry, and DUV), and finally 3) defects between different devices. We were able to find evidence of transferable processing defects.