Direct nitridation of 4H-SiC(0001) surface by H2/N2 treatment

Conditions for the direct nitridation of the 4H-SiC(0001) surface by H2/N2 treatment and resulting surface structure were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED). The FTIR analysis probed both Si–H stretching vibration with back-bond containing N atoms and Si–N stretching vibration on the nitrided surface, while XPS analysis revealed the formation of an NSi3 structure with N density of ~1 × 1015 cm−2. The LEED pattern for the H2/N2 treated surface exhibited a ( × )R30° superstructure. The results indicate that H2/N2 treatment produces a highly ordered H-terminated nitrided surface.