Aspects of the disclosure provide a method of preparing a focused ion beam (FIB) sample and analyzing the sample in an electron microscope system. The method can include forming, over a substrate, a target film having a thickness of less than a threshold corresponding to a limit for FIB requirements, and forming a supporting film over the target film. The method can also include obtaining a FIB sample that includes a portion of the target film and a portion of the supporting film and. The method can further include analyzing the obtained portion of the target film in an electron microscope system.