Towards vertical Schottky diodes on bulk cubic silicon carbide (3C-SiC)

In this paper, we demonstrate the feasibility of fabricating vertical Schottky diodes on bulk cubic silicon carbide (3C-SiC) material obtained by combining sublimation epitaxy and chemical vapor deposition, starting from 4°-off axis 4H-SiC. First, the good quality of the epilayers grown with this method was demonstrated by morphological and structural analyses. Then, fabricated vertical Pt/3C-SiC Schottky diodes exhibited an ideality factor of 1.21 and a barrier height of 0.6 eV, as determined by thermionic emission model. The temperature dependent forward current analysis indicated the formation of an inhomogeneous barrier, which has been related with the presence of conductive surface defects, detected by nanoscale local current measurements. On the other hand, the reverse leakage current could be described by thermionic field emission model, including image force lowering. These findings demonstrate the viability of the proposed approach for bulk 3C-SiC growth for device fabrication. The material quality and the feasibility of fabricating vertical diodes based on 3C-SiC with a low barrier pave the way for the application of this polytype for medium-voltage power devices.