The Application of Advanced Nano-Techniques in Failure Analysis for Different Failure Mechanism

摘要

With multi-metal layers and scaling down we occurred many difficulties in FA (Failure Analysis). Failure isolation for FA has more challenge with smaller defects and process changes. Conventional FA techniques couldn't meet need of analysis, so the advanced nano-techniques must be developed and applied in FAn^[1]-[2]n. By characterizing the electrical behavior on devices, these FA techniques (for example nanoprobing, EBAC, C-AFM, etc) precisely locates defects before any PF A is performed and allows for deeper understanding of the root cause. Nanoprobing are commonly utilized to measure electrical characterization with nanoscale area and under-layer circuit in F A lab. EBAC applications are to locate the high resistance, open circuit of interconnection, the connected path of a circuit, etc. The main application of Conductive Atomic Force Microscope (C-AFM) for high/low resistance and junction leakages differentiation had proven to be very useful in determining the failure mechanism. In this paper, the principle of advanced FA nano-techniques were introduced simply. Then three real cases with different failure mechanism were shared with applying these nano-techniques. In first case nanoprobing help to confirm resistive/open failure; in second case EBAC analysis revealed short failure between adjacent metal lines; in third case C-AFM technique was applied to find out implant/crystal defect which caused timing delay failure.