The purpose of analytical tools is to identify the composition and origin of anomalies. During physical analysis, the focused ion beam (FIB) tool is used to prepare samples for high-resolution imaging such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Imaging tools can be used to measure critical dimensions, observe anomalies, or provide elemental analysis through energy dispersive spectroscopy (EDS). If needed, EDS can be complemented with additional surface analysis techniques such as Auger, secondary ion mass spectrometry (SIMS), or Fourier transform infrared (FTIR) spectroscopy.
The focused ion beam tool is used to prepare sample x-sections as part of the physical analysis. A beam of highly accelerated gallium ions is used to create controlled microscopic cuts. X-sections of this type are commonly used to review anomalies and check critical dimensions. By adding special chemical gases, the tool can also be used to deposit materials. A combination of cutting and deposition are used to make circuit edits. Such edits allow for micro-probing or alteration of the functionality of the circuitry, such as trimming of diffusion or adding resistance during functional debug.
Scanning electron microscopy is used during sample preparation, high-resolution imaging, and elemental analysis. SEM is based on exposing a surface to a scanning, primary electron beam and analyzing the reflected energy from secondary, backscatter, or Auger electrons, and X-rays. At low beam acceleration, the SEM can also be used in various forms of voltage contrast imaging.
Transmission Electron Microscopy is used for ultra-high-resolution imaging and analysis. The high energy electron beam of a TEM can pass through a very thin sample. Electron transmission is based mostly on sample thickness, material density, and crystal lattice interactions. The transmitted electron beam can be used to form bright field, dark field, or diffraction images. Small beam size and limited sample interaction volume enable highly localized EDS with the TEM.