Miniaturization of today’s semiconductor devices and increased complexity of transistor architecture have resulted in gradually shrinking defect sizes. A direct consequence to this is the diminished chance of catching defects in the Transmission Electron Microscope (TEM) on the initial lamella, prompting the need to convert the TEM lamellas to analyze them from a different angle. In this work, a reliable step-by-step procedure to perform in-situ TEM lamella conversion is detailed. The applicability of the method is successfully validated on defective sub-20nm FinFET samples. Two different initial lamella types –planar and cross-sectional – are featured in the case studies to demonstrate the method’s versatility.