Precision Solutions for Electronic Materials

3D imaging of SiC MOSFET power device architecture and dopant regions can be performed by FIB-SEM tomography using 30 kV Ga-FIB and an in-column detector sensitive to low-energy SE. However, manual or conventional automatic segmentation of such data to examine the structure of each dopant zone separately and unambiguously is not possible.

AI-based segmentation provides a clean separation of the different dopant types and levels. 3D surface representations of dopant zones segmented in this way enable thorough evaluation of implant distributions, as visualizing their overall shape in 3D provides more information about deviations from the intended distributions than simply viewing individual 2D images. This information helps engineers improve yield and reduce failures of SiC power semiconductors.

Power devices are essential in controlling systems across various sectors, with silicon-based devices still predominant, although new materials and architectures are emerging. The performance of devices like Insulated Gate Bipolar Transistors (IGBTs) relies on healthy junctions. Simple preparation methods, such as cleaving or FIB milling, facilitate quick cross-sectional evaluations.

Previously this was limited to standard imaging or ex-situ electrical measurements. However, it is now possible to obtain detailed information on the junctions using in-situ probing techniques, such as electron beam induced current (EBIC) and passive voltage contrast (PVC). These techniques were employed to visualize the dopant structure and depletion zones, revealing that the beam voltage impacts measurements of depletion zone width. Overall, the study demonstrated a rapid method for evaluating junctions in intact IGBT devices with great potential to improve failure analysis of power electronic devices.