A correlative study of silicon carbide power devices using atom probe tomography and transmission electron microscopy.

Atom probe tomography is used to characterize the 3D Al dopant distribution within the gate diffusion region of a deconstructed SiC n-channel junction field effect transistor. The data reveals extensive inhomogeneities in the dopant distribution, which manifests as large Al clusters - some of which are ring-shaped and indicative of dopant segregation to lattice defects in the SiC. The presence of defects in the SiC is confirmed by transmission electron microscopy of an identical region. Factors that may impact the atom probe data quality and consequently complicate data interpretation are considered, and their severity evaluated. The possible origin of the lattice defects in the SiC and the corresponding implications for device performance and reliability are also discussed. Overall, the utility of atom probe tomography and correlative transmission electron microscopy for revealing potential failure mechanisms of next-generation semiconductor devices is demonstrated.