Determination of the valence band offset of a mu c-C/c-Si(100) heterojunction using low energy yield spectroscopy

The valence band offset developed in the heterostructure formed by depositing carbon on a Si(100) substrate was determined using a combination of low energy yield spectroscopy and x-ray photoemission spectroscopy. The spontaneous formation of an SiC layer between the crystalline silicon substrate and the carbon film was observed. Valence band offsets of 0.77 +/- 0.08 eV at the SiC/c-Si interface and 1.55 +/- 0.08 eV for the mu c-C/SiC interface were found. Taking into account the band bending at the SiC layer after the microcrystalline graphite layer formation, the valence band offset between the silicon substrate and the carbon layer was evaluated to be 0.63 +/- 0.08 eV, with the valence band edge of the carbon film being at higher energy than that of the silicon