Hydrogen Nanochemistry Achieving Clean and Pre-Oxidized Silicon Carbide Surface Metallization

We review H-induced metallization of clean and pre-oxidized 3C-SiC(100) 3x2 surfaces, the 1(st) example of a semiconductor surface metallization by H. These investigations are based on core level and valence band photoemission spectroscopies using synchrotron radiation, infrared absorption spectroscopy, and scanning tunneling microscopy and spectroscopy. These results are also compared to recent ab-initio calculations. This unexpected behavior results from an asymmetric attack of Si-dimers located below the surface creating dangling bond defects and from H atoms terminating top-surface dangling bonds leading overall to large charge transfer to the surface and sub-surface regions.