Low-temperature formation of Mg/n-type 4H-SiC ohmic contacts with atomically flat interface by lowering of Schottky barrier height

To obtain an ohmic contact with a flat interface using a low-temperature process, we investigated the behavior of Schottky barrier height (SBH) at the Mg/n-type 4H-SiC interface to low-temperature annealing. Our results revealed that annealing at 200 degrees C reduced SBH; a low SBH of 0.28 eV was obtained on the lightly doped substrate. Atomic force microscopy measurements revealed negligible increase in the surface roughness after Mg deposition and annealing. Using the low-temperature process, a contact resistivity of 6.5 x 10(-5) omega center dot cm(2) was obtained on the heavily doped substrate, which is comparable to Ni/4H-SiC subjected to annealing of above 950 degrees C.

Automated summary

In this study, we achieved an ohmic contact with a flat interface using low-temperature annealing. Our results showed that annealing at 200 degrees C reduced the Schottky barrier height and had minimal effect on surface roughness. By utilizing the low-temperature process, we obtained contact resistivity comparable to high-temperature annealing on heavily doped substrates.