Epitaxial Ultrathin MgB2 Films on C-Terminated 6H-SiC (000(1)over-bar) Substrates Grown by HPCVD

Smooth and uniform epitaxial ultrathin MgB2 films are desired for various electronic applications including hot-electron bolometers and single-photon detectors. However, the growth of ultrathin MgB2 films on SiC substrates using the Hybrid Physical-Chemical Vapor Deposition was dominated by the Volmer-Weber or island growth mode, which limited the minimum thickness for a conductive MgB2 film. Here we show the results of a study on the very early stage of the MgB2 film growth. We find that the root-mean-squared roughness and grain connectivity of ultrathin MgB2 films grown on C-terminated 6H-SiC(000 (1) over bar) substrate is much better than those on Si-terminated substrate. The result provides a simple solution to growing high-quality ultrathin MgB2 films for applications.

Automated summary

The growth of ultrathin MgB2 films on C-terminated 6H-SiC substrate results in better surface smoothness and grain connectivity compared to films grown on Si-terminated substrate, providing a simple solution for high-quality ultrathin MgB2 films in electronic applications.