High temperature measurements of metal contacts on epitaxial graphene

Electrical characteristics of Cr/Au and Ti/Au metal contacts on epitaxial graphene on 4H-SiC showed significant variations in resistance parameters at 3000 K. These parameters decreased substantially as the temperature increased to 673 K. The work function, binding energy, and diffusion energy of the deposited metals were used to explain these observed variations. The quantitative analysis of our data demonstrates that non-reactive metals with higher work functions result in lower contact resistance, which can be further decreased by 70% using appropriate annealing. These results provide important information when considering epitaxial graphene for high temperature applications.