Ideal ohmic contact to n-type 6H-SiC by reduction of Schottky barrier height

We formed ideal Ti Ohmic contacts on an n-type 6H-SiC epitaxial layer by reducing Schottky barrier heights. The ideal contacts were realized by utilizing ideal SiC surfaces formed under processes that intend to lower the density of surface states. As the first process to form the ideal surfaces, SiC surfaces were flattened by oxidation followed by HF etching. Further, the ideal SiC surfaces in terms of passivation of surface states were formed by immersing the flat SiC surfaces in boiling water. Ti electrodes thus formed had Ohmic properties with excellent I-V characteristic linearity without the use of heavy doping and high-temperature annealing. (C) 1997 American Institute of Physics.