Ag growth on 3C-SiC(001) c(2x2) C-terminated and c(4x2) Si-terminated surfaces

We use core level (Si 2p, C 1s, Ag 3d) and valence band photoemission spectroscopies using Mg Kalpha, Ne I and synchrotron radiation light source, to investigate room temperature Ag growth on both C-terminated c(2x2) and Si-terminated c(4x2) 3C-SiC(001) surface reconstructions. In both cases the interface is shown to be non-reactive with no carbide or silicide formation. For the carbon-terminated 3C-SiC(001)c(2x2) surface, we find a Stransky-Krastanov growth mode. Ultraviolet photoemission spectroscopy from valence-band for n-type, C-terminated SiC shows metallization of the thin film with a clear Fermi edge and an ohmic Ag/3C-SiC(001)c(2x2) contact. Such a metallization is also to occur on the Si-terminated c(4x2) surface reconstruction with however, a much broader Ag 4d line, when compared to the C-terminated c(2x2) surface. This indicates a somewhat stronger Ag-substrate interaction on the c(2x2) C-terminated compared to the Si-terminated c(4x2).