The State-of-the-Art FinFET technology has been widely adopted in the industry, typically at 14 nm and below technology nodes. As fin dimensions are pushed into the nanometer scale, process complexity is highly escalated, posing great challenges for physical failure analysis. Meanwhile, the accelerated cycles of learning for new technology nodes demand high accuracy and fast turnaround time to solve the material and interface issues pertaining to semiconductor processing or device failure. In this paper, we report a case study of fin related defect that caused device failure. Several analytical techniques, namely, Scanning Electron Microscopy (SEM), plan-view and cross-section Transmission Electron Microscopy (TEM) with Energy Dispersive X-ray spectroscopy (EDX), Electron Energy Loss Spectroscopy (EELS) and Z-contrast tomography were employed to characterize the defect and identify root-cause, leading to the resolution of this issue.