Evaluation of Grain-Boundary Conduction of Dense AlN-SiC Solid Solution by Scanning Nonlinear Dielectric Microscopy

Dense and elemental homogeneous 2H AlN-SiC solid solution doped with Al and C was fabricated by using spark plasma sintering. The p-type electrical conduction of the sample was confirmed by measurements of electrical conductivities and Seebeck coefficient. Dopant profiling of the sample by scanning nonlinear dielectric microscopy showed that the AlN-SiC grains respond to p-type electrical conduction. These results indicated that added Al and C were dissolved to the grains and acted as p-type dopants. In contrast, the grain boundaries did not show any response, suggesting the presence of depletion layer in the boundary.