Ti/Al/Au ohmic contacts to p-type 4H-SiC

Ti/Al/Au ohmic contacts to p-type 4H-SiC with different Ti composition are reported. The contact with high Ti content yields a lower specific contact resistivity (ρ
_C
) of 6.4×10
^-5
Ωcm
²
, compared with the low-Ti contained contact. The annealed surface morphology and phase products for these contacts are examined by Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) spectra, respectively. These results reveal that rich Ti prevents the large agglomerate grains from the liquid Al during annealing, which is beneficial for interfacial reaction and formation of the ohmic contact.