Improved Schottky Contacts on n-type SiC using ZrB$_{2}$

We present results on ZrB$_{2}$ Schottky contacts deposited on n-type SiC by DC magnetron sputtering at temperatures between 20 $^{o}$C and 800 $^{o}$C. The Schottky barrier heights determined by current-voltage measurements, increased with the deposition temperature from 0.87 eV for contacts deposited at 20 $^{o}$C to 1.07 eV for those deposited at 600 $^{o}$C. The RBS spectra of these contacts revealed a substantial decrease in oxygen peak with increase in the deposition temperature and showed no reaction at the ZrB$_{2}$/SiC interface. The barrier heights of the contacts annealed in nitrogen for 20 mins at 200 $^{o}$C to 500 $^{o}$C using a rapid thermal processor revealed only a slight increase. These results indicate improvement in the electrical properties and thermal stability of ZrB$_{2}$ on n-type SiC when the contacts are deposited at elevated temperatures, making them attractive for high temperature applications.