Comparison of Epitaxial Graphene grown on SiC(0001) and SiC(000$\bar{1}$)

Epitaxial graphene (EG) has been grown on both the Si-terminated (0001) and C-terminated (000$\bar{1}$) faces of 4H and 6H SiC. It has been shown that EG on the C-terminated face has substantially higher carrier mobility ($\sim 25,000 \textrm{cm}^2/\textrm{V}\cdot\textrm{s}$) , although EG on either face shows similar intrinsic carrier density and magnetoresistance (MR) characteristic of graphene [1,2]. In this work, we use STM, LEED and Auger spectroscopy to compare the different growth methods and resulting morphologies of EG grown on the silicon- and carbon-terminated faces of SiC. UHV sublimation of silicon from SiC(0001) results in controllable growth of 1-5 ML of EG, with the thickness determined predominantly by the growth temperature. EG growth on SiC(000$\bar{1}$) via Si-sublimation is done in a low vacuum induction furnace, resulting in 5-30 ML thick films. Since MR results indicate that transport is dominated by an EG layer near the SiC interface [2], we will discuss methods to access the EG/SiC(000$\bar{1}$) interface by STM. [1] C. Berger, et al., J. Phys. Chem. B 108,19912 (2004). [2] C. Berger, et al., Science 312, 1191 (2006)