Defects introduced by the solid state reactions between tungsten and silicon carbide have been
studied using deep level transient spectroscopy (DLTS) and Laplace DLTS. W/4H-SiC Schottky
barrier diodes were isochronally annealed in the 100–1100 C temperature range. Phase
composition transitions and the associated evolution in the surface morphology were investigated
using x-ray diffraction (XRD) and scanning electron microscopy (SEM). After annealing at
1100 C, the E0.08, E0.15, E0.23, E0.34, E0.35, E0.61, E0.67, and E0.82 defects were observed. Our study
reveals that products of thermal reactions at the interface between tungsten and n-4H-SiC may
migrate into the semiconductor, resulting in electrically active defect states in the bandgap.